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[PATCH v33 3/5] Subscripting for jsonb
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* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v29 3/6] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v30 3/6] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v31 3/6] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v35 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v32 3/6] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v34 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v32 3/6] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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 filename="v49-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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 filename="v49-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v39] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 412 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 981 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index ce09ad7375..0ef0f36e36 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..b91a140494
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,412 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 12557ce3af..1925cd8026 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4153,58 +4201,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4476,7 +4472,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4634,7 +4631,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4792,10 +4790,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4848,11 +4846,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4869,7 +4867,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4900,7 +4898,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4923,7 +4921,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4955,7 +4953,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5003,7 +5001,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5019,7 +5017,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5030,7 +5028,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5064,7 +5062,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index e6c7b070f6..82570cce6f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10943,6 +10943,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 28240bdce3..3c0ee2a81b 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..eefe5d55ee 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..5b8a51f712 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--65dnqzlcwvdscbys--





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v40 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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 filename="v49-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

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

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

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

The original idea belongs to Oleg Bartunov.

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

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


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



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
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* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
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* [PATCH v38] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb of type object and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 +++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 +++++++-
 src/backend/utils/adt/jsonbsubs.c   | 282 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 +++++++++---------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 273 ++++++++++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 ++++++++-
 10 files changed, 852 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..cad7b02559 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is {"1": 1}
+UPDATE table_name SET jsonb_field[1] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index ce09ad7375..0ef0f36e36 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..b58efb7c0d
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,282 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subexpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			subexpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subexpr = coerce_to_target_type(pstate,
+											subexpr, exprType(subexpr),
+											TEXTOID, -1,
+											COERCION_ASSIGNMENT,
+											COERCE_IMPLICIT_CAST,
+											-1);
+			if (subexpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subexpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  sbsrefstate->upperindex,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb of object
+	 * type and proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+		newSource->type = jbvObject;
+		newSource->val.object.nPairs = 0;
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  sbsrefstate->upperindex,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 12557ce3af..1925cd8026 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4153,58 +4201,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4476,7 +4472,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4634,7 +4631,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4792,10 +4790,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4848,11 +4846,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4869,7 +4867,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4900,7 +4898,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4923,7 +4921,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4955,7 +4953,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5003,7 +5001,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5019,7 +5017,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5030,7 +5028,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5064,7 +5062,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index e6c7b070f6..82570cce6f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10943,6 +10943,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 28240bdce3..3c0ee2a81b 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..85f8364d70 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,277 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"0": 1}
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..5b8a51f712 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--hletpuqfhzttgv77--





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Remove restrictions in recursive query
@ 2025-03-27 16:02 Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 17:00 ` Re: Remove restrictions in recursive query David G. Johnston <[email protected]>
  0 siblings, 2 replies; 214+ messages in thread

From: Renan Alves Fonseca @ 2025-03-27 16:02 UTC (permalink / raw)
  To: pgsql-hackers

Hi,

I'm confused about what we should allow in a recursive query. For example,
in the following query:

WITH RECURSIVE t1 AS ( SELECT 1 UNION  SELECT generate_series(2,3) FROM t1
ORDER BY  1 DESC) SELECT * FROM t1 ;

The parser attaches the "order by" clause to the "union" operator, and then
we error out with the following message: "ORDER BY in a recursive query is
not implemented"

The comment in the code (parser_cte.c:900) says "Disallow ORDER BY and
similar decoration atop the UNION". Then, if we wrap the recursive clause
around parentheses:

WITH RECURSIVE t1 AS ( SELECT 1 UNION  (SELECT generate_series(2,3) FROM t1
ORDER BY  1 DESC)) SELECT * FROM t1 ;

It works as expected. So, do we support the ORDER BY in a recursive query
or not? If the answer is yes, I suggest one of the following modifications:
1. Change the error message to something like "ORDER BY at the top level of
a recursive query is not implemented. HINT: wrap the respective statement
around ()"
2. (preferred) Modify the parser or simply remove these checks to allow the
first query.

If the answer is no, then there is a minor bug that allows us to bypass the
check. Even though the ORDER BY happens inside the working table, I think
it can be a useful feature combined with LIMIT and OFFSET.

There is a similar restriction regarding GROUP BY. But in this case, the
error message is very clear and it is consistent with the comment in the
code. I suggest removing this restriction as well in order to improve
PostgreSQL's capabilities to process graph data. For example, counting the
number of paths in a DAG can be computed more efficiently using an
aggregation in each step.

I don't know what the standard says about this, but it certainly does not
allow DISTINCT ON in the recursive query, while PostgreSQL does support it.
So, we could eventually skip the specs in this case to be more consistent
since a DISTINCT ON has many similarities with a GROUP BY.

I did some tests, and it is enough to remove the check regarding the GROUP
BY. The machinery to perform the GROUP BY in a recursive clause is already
there.

Of course, if it is the case, I would be glad to send a patch.

Best regards,
Renan Fonseca


^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
@ 2025-03-27 16:37 ` Robert Haas <[email protected]>
  2025-03-27 16:39   ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 18:03   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-28 18:59   ` Re: Remove restrictions in recursive query Nico Williams <[email protected]>
  1 sibling, 3 replies; 214+ messages in thread

From: Robert Haas @ 2025-03-27 16:37 UTC (permalink / raw)
  To: Renan Alves Fonseca <[email protected]>; +Cc: pgsql-hackers

On Thu, Mar 27, 2025 at 12:02 PM Renan Alves Fonseca
<[email protected]> wrote:
> WITH RECURSIVE t1 AS ( SELECT 1 UNION  SELECT generate_series(2,3) FROM t1 ORDER BY  1 DESC) SELECT * FROM t1 ;
>
> The parser attaches the "order by" clause to the "union" operator, and then we error out with the following message: "ORDER BY in a recursive query is not implemented"
>
> The comment in the code (parser_cte.c:900) says "Disallow ORDER BY and similar decoration atop the UNION". Then, if we wrap the recursive clause around parentheses:
>
> WITH RECURSIVE t1 AS ( SELECT 1 UNION  (SELECT generate_series(2,3) FROM t1 ORDER BY  1 DESC)) SELECT * FROM t1 ;
>
> It works as expected. So, do we support the ORDER BY in a recursive query or not?

A recursive CTE effectively takes two queries that will be run as
arguments. For some reason, instead of choosing syntax like WITH
RECURSIVE t1 AS BASE_CASE (initial_query) RECURSIVE_CASE
(iterated_query), somebody chose WITH RECURSIVE t1 AS (initial_query
UNION iterated_query) which really doesn't make it very clear that we
need to be able to break it apart into two separate queries, one of
which will be run once and one of which will be iterated.

It's not a problem if UNION ALL is used within the initial_query and
it's not a problem if UNION ALL is used within the iterated_query. But
you can't apply ORDER BY to the result of the UNION, because the UNION
is kind of fake -- we're not running the UNION as a single query,
we're running the two halves separately, the first once and the second
as many times as needed.

-- 
Robert Haas
EDB: http://www.enterprisedb.com





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
@ 2025-03-27 16:39   ` Robert Haas <[email protected]>
  2 siblings, 0 replies; 214+ messages in thread

From: Robert Haas @ 2025-03-27 16:39 UTC (permalink / raw)
  To: Renan Alves Fonseca <[email protected]>; +Cc: pgsql-hackers

On Thu, Mar 27, 2025 at 12:37 PM Robert Haas <[email protected]> wrote:
> It's not a problem if UNION ALL is used within the initial_query and
> it's not a problem if UNION ALL is used within the iterated_query. But
> you can't apply ORDER BY to the result of the UNION, because the UNION
> is kind of fake -- we're not running the UNION as a single query,
> we're running the two halves separately, the first once and the second
> as many times as needed.

Oops. The two UNION ALL references in the first part of this paragraph
should have said ORDER BY.

-- 
Robert Haas
EDB: http://www.enterprisedb.com





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
@ 2025-03-27 18:03   ` Renan Alves Fonseca <[email protected]>
  2025-03-27 18:09     ` Re: Remove restrictions in recursive query David G. Johnston <[email protected]>
  2 siblings, 1 reply; 214+ messages in thread

From: Renan Alves Fonseca @ 2025-03-27 18:03 UTC (permalink / raw)
  To: pgsql-hackers

On Thu, Mar 27, 2025 at 5:38 PM Robert Haas <[email protected]> wrote:
> It's not a problem if UNION ALL is used within the initial_query and
> it's not a problem if UNION ALL is used within the iterated_query. But
> you can't apply ORDER BY to the result of the UNION, because the UNION
> is kind of fake -- we're not running the UNION as a single query,
> we're running the two halves separately, the first once and the second
> as many times as needed.

I understand that we can only apply ORDER BY separately in the
initial/iterated query. What disturbs me here is that the UNION
operator has associativity precedence over the ORDER BY only when
inside a recursive CTE. Consider the following query:

SELECT 1 UNION SELECT 1 GROUP BY 1;

It returns 2 rows. The GROUP BY clause attaches to the second
selectStmt without the need to add parenthesis. I would expect the
same syntax inside a recursive CTE.





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 18:03   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
@ 2025-03-27 18:09     ` David G. Johnston <[email protected]>
  2025-03-27 18:21       ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  0 siblings, 1 reply; 214+ messages in thread

From: David G. Johnston @ 2025-03-27 18:09 UTC (permalink / raw)
  To: Renan Alves Fonseca <[email protected]>; +Cc: pgsql-hackers

--000000000000fbcad8063156dd5c
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Thu, Mar 27, 2025 at 11:03=E2=80=AFAM Renan Alves Fonseca <renanfonseca@=
gmail.com>
wrote:

> On Thu, Mar 27, 2025 at 5:38=E2=80=AFPM Robert Haas <[email protected]=
m> wrote:
> > It's not a problem if UNION ALL is used within the initial_query and
> > it's not a problem if UNION ALL is used within the iterated_query. But
> > you can't apply ORDER BY to the result of the UNION, because the UNION
> > is kind of fake -- we're not running the UNION as a single query,
> > we're running the two halves separately, the first once and the second
> > as many times as needed.
>
> I understand that we can only apply ORDER BY separately in the
> initial/iterated query. What disturbs me here is that the UNION
> operator has associativity precedence over the ORDER BY only when
> inside a recursive CTE. Consider the following query:
>
> SELECT 1 UNION SELECT 1 GROUP BY 1;
>
> It returns 2 rows. The GROUP BY clause attaches to the second
> selectStmt without the need to add parenthesis. I would expect the
> same syntax inside a recursive CTE.
>

There is distinct behavior between group by and order by here.  You seem to
be mixing them up.



^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 18:03   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:09     ` Re: Remove restrictions in recursive query David G. Johnston <[email protected]>
@ 2025-03-27 18:21       ` Renan Alves Fonseca <[email protected]>
  2025-03-27 18:32         ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 21:17         ` Re: Remove restrictions in recursive query Tom Lane <[email protected]>
  0 siblings, 2 replies; 214+ messages in thread

From: Renan Alves Fonseca @ 2025-03-27 18:21 UTC (permalink / raw)
  To: David G. Johnston <[email protected]>; +Cc: pgsql-hackers

On Thu, Mar 27, 2025 at 7:10 PM David G. Johnston
<[email protected]> wrote:
>
> There is distinct behavior between group by and order by here.  You seem to be mixing them up.
>
> From Select:
>
> select_statement is any SELECT statement without an ORDER BY, LIMIT, FOR NO KEY UPDATE, FOR UPDATE, FOR SHARE, or FOR KEY SHARE clause. (ORDER BY and LIMIT can be attached to a subexpression if it is enclosed in parentheses. Without parentheses, these clauses will be taken to apply to the result of the UNION, not to its right-hand input expression.)
>
> This is the exact same parsing precedence order by is being given in the recursive CTE query situation presented earlier.
>
> David J.
>

You're right. I'm really mixing these 2 here. Thanks for the clarification.

I'll assume that the silence about allowing GROUP BY means it is not a
great idea...





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 18:03   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:09     ` Re: Remove restrictions in recursive query David G. Johnston <[email protected]>
  2025-03-27 18:21       ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
@ 2025-03-27 18:32         ` Robert Haas <[email protected]>
  2025-03-27 21:21           ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  1 sibling, 1 reply; 214+ messages in thread

From: Robert Haas @ 2025-03-27 18:32 UTC (permalink / raw)
  To: Renan Alves Fonseca <[email protected]>; +Cc: David G. Johnston <[email protected]>; pgsql-hackers

On Thu, Mar 27, 2025 at 2:21 PM Renan Alves Fonseca
<[email protected]> wrote:
> You're right. I'm really mixing these 2 here. Thanks for the clarification.

It looks like GROUP BY binds to the particular UNION branch but ORDER
BY binds to the UNION as a whole:

robert.haas=# select 2 union all select 1;
 ?column?
----------
        2
        1
(2 rows)

robert.haas=# select 2 union all select 1 order by 1;
 ?column?
----------
        1
        2
(2 rows)

robert.haas=# select 2 union all select 1 group by 1;
 ?column?
----------
        2
        1
(2 rows)

> I'll assume that the silence about allowing GROUP BY means it is not a
> great idea...

I don't think there's really anything to keep you from doing this --
just put the grouping operation where you refer to the recursive CTE,
instead of inside the recursive CTE itself. I think allowing it to
appear inside the recursive CTE would be rather confusing -- it's
probably best if the mandatory UNION operation is at the top level.

-- 
Robert Haas
EDB: http://www.enterprisedb.com





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 18:03   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:09     ` Re: Remove restrictions in recursive query David G. Johnston <[email protected]>
  2025-03-27 18:21       ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:32         ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
@ 2025-03-27 21:21           ` Renan Alves Fonseca <[email protected]>
  2025-03-27 21:50             ` Re: Remove restrictions in recursive query Tom Lane <[email protected]>
  0 siblings, 1 reply; 214+ messages in thread

From: Renan Alves Fonseca @ 2025-03-27 21:21 UTC (permalink / raw)
  To: Robert Haas <[email protected]>; +Cc: David G. Johnston <[email protected]>; pgsql-hackers

On Thu, Mar 27, 2025 at 7:32 PM Robert Haas <[email protected]> wrote:
>
> > I'll assume that the silence about allowing GROUP BY means it is not a
> > great idea...
>
> I don't think there's really anything to keep you from doing this --
> just put the grouping operation where you refer to the recursive CTE,
> instead of inside the recursive CTE itself. I think allowing it to
> appear inside the recursive CTE would be rather confusing -- it's
> probably best if the mandatory UNION operation is at the top level.
>

I don't think I was clear enough about the proposed improvements. I
hope this example will clarify.

Consider a table representing the edges of a directed acyclic graph.
The following lines will create an example of such a table.

-- create DAG example
\set output_degree 10
\set maxN 20000

create temp table dag(source,target) as
       (with recursive t1(source,target) as
             (select 1,1
           union
     select target, target * i from t1, generate_series(2,:output_degree +1) i
     where target*i< :maxN
     ) select * from t1 where source!=target );

Then, suppose we want to count the number of distinct paths from the
root (1) to all sink nodes. We use the following auxiliary table for
the sink nodes:

create temp table sink_nodes(node) as
       (select target from dag except select source from dag);

The solution supported in PostgreSQL is the following:

with recursive t1(node,path) as
     (select 1,array[1]
           union
     select dag.target, t1.path||dag.target
     from t1 join dag on t1.node=dag.source
    ) select count(*) from t1 join sink_nodes using (node) ;

This query enumerates every path and probably has something like
exponential complexity on the number of edges. It gives these results
in my laptop:
  count
---------
 1114163
(1 row)
Time: 8121.044 ms (00:08.121)

The solution using GROUP BY in the recursive query is the following:

with recursive t1(node,nb_path) as
     (select 1,1::numeric
           union all
      (select dag.target, sum(nb_path)
      from t1 join dag on t1.node=dag.source
      group by 1)
     ) select sum(nb_path) from t1 join sink_nodes using (node) ;

At every iteration step, we sum the number of paths that arrived at a
given node. That is another class of algorithm complexity. The first
query cannot scale to larger inputs, while this one can scale. Here is
the result:

   sum
---------
 1114163
(1 row)
Time: 27.123 ms

I hope this example made clear that allowing the GROUP BY in the
recursive clause significantly increases the capabilities of doing
analytics on graph data, and it is not only syntax sugar. Please let
me know if there is another way of handling this problem efficiently
without the proposed change.

Thanks again for your attention,
Renan





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 18:03   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:09     ` Re: Remove restrictions in recursive query David G. Johnston <[email protected]>
  2025-03-27 18:21       ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:32         ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 21:21           ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
@ 2025-03-27 21:50             ` Tom Lane <[email protected]>
  2025-03-27 22:29               ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  0 siblings, 1 reply; 214+ messages in thread

From: Tom Lane @ 2025-03-27 21:50 UTC (permalink / raw)
  To: Renan Alves Fonseca <[email protected]>; +Cc: Robert Haas <[email protected]>; David G. Johnston <[email protected]>; pgsql-hackers

Renan Alves Fonseca <[email protected]> writes:
> The solution using GROUP BY in the recursive query is the following:

> with recursive t1(node,nb_path) as
>      (select 1,1::numeric
>            union all
>       (select dag.target, sum(nb_path)
>       from t1 join dag on t1.node=dag.source
>       group by 1)
>      ) select sum(nb_path) from t1 join sink_nodes using (node) ;

This is not about the GROUP BY; it's about the SUM().
If you try this example you get

regression=# with recursive t1(node,nb_path) as
     (select 1,1::numeric
           union all
      (select dag.target, sum(nb_path)
      from t1 join dag on t1.node=dag.source
      group by 1)
     ) select sum(nb_path) from t1 join sink_nodes using (node) ;
ERROR:  aggregate functions are not allowed in a recursive query's recursive term
LINE 4:       (select dag.target, sum(nb_path)
                                  ^

The code says that that restriction is from the SQL spec, and
it seems to be correct as of SQL:2021.  7.17 <query expression>
SR 3)j)ix)5)C) says

    C) WQEi shall not contain a <query specification> QS such that QS
       immediately contains a <table expression> TE that contains a
       <query name> referencing WQNX and either of the following is true:

      I) TE immediately contains a <having clause> that contains a
         <set function specification>.

      II) QS immediately contains a <select list> SL that contains
          either a <window function>, or a <set function
          specification>, or both.

(<set function specification> is spec-ese for "aggregate function
call")

I don't know the SQL committee's precise reasoning for this
restriction, but I suspect it's because the recursive query
expansion is not well-defined in the presence of an aggregate.
The spec has an interesting comment at the bottom of sub-rule ix:

    NOTE 310 — The restrictions insure that each WLEi, viewed as a
    transformation of the query names of the stratum, is monotonically
    increasing. According to Tarski’s fixed point theorem, this
    insures that there is a fixed point. The General Rules use
    Kleene’s fixed point theorem to define a sequence that converges
    to the minimal fixed point.

			regards, tom lane





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 18:03   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:09     ` Re: Remove restrictions in recursive query David G. Johnston <[email protected]>
  2025-03-27 18:21       ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:32         ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 21:21           ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 21:50             ` Re: Remove restrictions in recursive query Tom Lane <[email protected]>
@ 2025-03-27 22:29               ` Renan Alves Fonseca <[email protected]>
  2025-03-28 00:14                 ` Re: Remove restrictions in recursive query Tom Lane <[email protected]>
  0 siblings, 1 reply; 214+ messages in thread

From: Renan Alves Fonseca @ 2025-03-27 22:29 UTC (permalink / raw)
  To: Tom Lane <[email protected]>; +Cc: Robert Haas <[email protected]>; David G. Johnston <[email protected]>; pgsql-hackers

On Thu, Mar 27, 2025 at 10:50 PM Tom Lane <[email protected]> wrote:
>
> Renan Alves Fonseca <[email protected]> writes:
> > The solution using GROUP BY in the recursive query is the following:
>
> > with recursive t1(node,nb_path) as
> >      (select 1,1::numeric
> >            union all
> >       (select dag.target, sum(nb_path)
> >       from t1 join dag on t1.node=dag.source
> >       group by 1)
> >      ) select sum(nb_path) from t1 join sink_nodes using (node) ;
>
> This is not about the GROUP BY; it's about the SUM().

Cannot SUM() without GROUP BY, right? (I mean the SUM() in the recursive query)

> If you try this example you get
>
> regression=# with recursive t1(node,nb_path) as
>      (select 1,1::numeric
>            union all
>       (select dag.target, sum(nb_path)
>       from t1 join dag on t1.node=dag.source
>       group by 1)
>      ) select sum(nb_path) from t1 join sink_nodes using (node) ;
> ERROR:  aggregate functions are not allowed in a recursive query's recursive term
> LINE 4:       (select dag.target, sum(nb_path)
>                                   ^

Sorry, I forgot to mention that this query only works in my local hack
(I simply removed the check that raises this error message)

> The code says that that restriction is from the SQL spec, and
> it seems to be correct as of SQL:2021.  7.17 <query expression>
> SR 3)j)ix)5)C) says
>
>     C) WQEi shall not contain a <query specification> QS such that QS
>        immediately contains a <table expression> TE that contains a
>        <query name> referencing WQNX and either of the following is true:
>
>       I) TE immediately contains a <having clause> that contains a
>          <set function specification>.
>
>       II) QS immediately contains a <select list> SL that contains
>           either a <window function>, or a <set function
>           specification>, or both.
>
> (<set function specification> is spec-ese for "aggregate function
> call"

I suspected that this restriction came straight from the specs. I
understand that while the proposed solution can help in some specific
use cases, it is not enough to justify an exception to the spec.

> I don't know the SQL committee's precise reasoning for this
> restriction, but I suspect it's because the recursive query
> expansion is not well-defined in the presence of an aggregate.
> The spec has an interesting comment at the bottom of sub-rule ix:
>
>     NOTE 310 — The restrictions insure that each WLEi, viewed as a
>     transformation of the query names of the stratum, is monotonically
>     increasing. According to Tarski’s fixed point theorem, this
>     insures that there is a fixed point. The General Rules use
>     Kleene’s fixed point theorem to define a sequence that converges
>     to the minimal fixed point.
>
>                         regards, tom lane





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 18:03   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:09     ` Re: Remove restrictions in recursive query David G. Johnston <[email protected]>
  2025-03-27 18:21       ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:32         ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 21:21           ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 21:50             ` Re: Remove restrictions in recursive query Tom Lane <[email protected]>
  2025-03-27 22:29               ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
@ 2025-03-28 00:14                 ` Tom Lane <[email protected]>
  2025-03-28 18:42                   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  0 siblings, 1 reply; 214+ messages in thread

From: Tom Lane @ 2025-03-28 00:14 UTC (permalink / raw)
  To: Renan Alves Fonseca <[email protected]>; +Cc: Robert Haas <[email protected]>; David G. Johnston <[email protected]>; pgsql-hackers

Renan Alves Fonseca <[email protected]> writes:
> I suspected that this restriction came straight from the specs. I
> understand that while the proposed solution can help in some specific
> use cases, it is not enough to justify an exception to the spec.

Well, we extend the spec in lots of places.  I'd be okay with removing
this restriction if I were sure there were no bad consequences, but
it seems likely that there are some.  College math was way too long
ago for me to be sure about the "fixed-point" business ... but I think
what they may be on about is that rows produced by aggregation may not
be stable in the face of adding more and more rows via additions to
the recursion workspace.  In your example, I think it somewhat
accidentally doesn't matter: an underlying row might get picked up
and added to a dag.target-grouped row in one recursion step or
a different one, but then you sum all those sums in the top-level
query, so the top sum comes out the same regardless of just what sets
the intermediate grouped rows consisted of.  With a different query
construction though, that would matter.

			regards, tom lane





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 18:03   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:09     ` Re: Remove restrictions in recursive query David G. Johnston <[email protected]>
  2025-03-27 18:21       ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:32         ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 21:21           ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 21:50             ` Re: Remove restrictions in recursive query Tom Lane <[email protected]>
  2025-03-27 22:29               ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-28 00:14                 ` Re: Remove restrictions in recursive query Tom Lane <[email protected]>
@ 2025-03-28 18:42                   ` Renan Alves Fonseca <[email protected]>
  0 siblings, 0 replies; 214+ messages in thread

From: Renan Alves Fonseca @ 2025-03-28 18:42 UTC (permalink / raw)
  To: Tom Lane <[email protected]>; +Cc: Robert Haas <[email protected]>; David G. Johnston <[email protected]>; pgsql-hackers

On Fri, Mar 28, 2025 at 1:14 AM Tom Lane <[email protected]> wrote:
>
> Well, we extend the spec in lots of places.  I'd be okay with removing
> this restriction if I were sure there were no bad consequences, but
> it seems likely that there are some.  College math was way too long
> ago for me to be sure about the "fixed-point" business ... but I think
> what they may be on about is that rows produced by aggregation may not
> be stable in the face of adding more and more rows via additions to

After a quick math review, I'm quite convinced that the "fixed-point"
business applies only to the UNION [DISTINCT] case, in which the
relations can be seen as sets. Recursion with UNION ALL is a
completely different operation. I hope they mention that in the
standard. Consider this very basic recursive query:

WITH RECURSIVE t1 AS ( SELECT 1 UNION ALL SELECT * FROM t1) SELECT * FROM t1;

It does not converge. When using recursive UNION ALL it is the user
responsibility to create the conditions for convergence.

> the recursion workspace.  In your example, I think it somewhat
> accidentally doesn't matter: an underlying row might get picked up
> and added to a dag.target-grouped row in one recursion step or
> a different one, but then you sum all those sums in the top-level
> query, so the top sum comes out the same regardless of just what sets
> the intermediate grouped rows consisted of.  With a different query
> construction though, that would matter.

Not exactly accidental. I'm aware that the first GROUP BY runs in the
scope of the working table, and I'm aware that I can compose the sum
aggregates. Not every aggregate can be composed like that. The
following is the same query without the inner GROUP BY. As you've
mentioned, the SUM is much faster than COUNT (but still it has the
same complexity).

with recursive t1(node,nb_path) as
     (select 1,1::numeric
           union all
      (select dag.target, 1
      from t1 join dag on t1.node=dag.source)
     ) select sum(nb_path) from t1 join sink_nodes using (node) ;

Even if PostgreSQL allowed us to use GROUP BY in the recursive query,
we would be driving the intermediate steps, which feels wrong in a
declarative paradigm. Ideally, we would write the query above and
PostgreSQL would generate the most optimized execution that we've seen
before. I've seen that there is some ongoing work on PARTIAL
AGGREGATES. It would be beautiful if the optimizer could push down the
aggregate into the recursive clause. Does it sound possible?

Regards,
Renan





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
  2025-03-27 18:03   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 18:09     ` Re: Remove restrictions in recursive query David G. Johnston <[email protected]>
  2025-03-27 18:21       ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
@ 2025-03-27 21:17         ` Tom Lane <[email protected]>
  1 sibling, 0 replies; 214+ messages in thread

From: Tom Lane @ 2025-03-27 21:17 UTC (permalink / raw)
  To: Renan Alves Fonseca <[email protected]>; +Cc: David G. Johnston <[email protected]>; pgsql-hackers

Renan Alves Fonseca <[email protected]> writes:
> I'll assume that the silence about allowing GROUP BY means it is not a
> great idea...

Well, you can do grouping, ordering, or whatever else you want to the
result of the recursive WITH in the outer query level.  I don't see
any advantage in allowing an additional level of that inside the WITH.

			regards, tom lane





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
  2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
@ 2025-03-28 18:59   ` Nico Williams <[email protected]>
  2 siblings, 0 replies; 214+ messages in thread

From: Nico Williams @ 2025-03-28 18:59 UTC (permalink / raw)
  To: Robert Haas <[email protected]>; +Cc: Renan Alves Fonseca <[email protected]>; pgsql-hackers

On Thu, Mar 27, 2025 at 12:37:53PM -0400, Robert Haas wrote:
> A recursive CTE effectively takes two queries that will be run as
> arguments. For some reason, instead of choosing syntax like WITH
> RECURSIVE t1 AS BASE_CASE (initial_query) RECURSIVE_CASE
> (iterated_query), somebody chose WITH RECURSIVE t1 AS (initial_query
> UNION iterated_query) which really doesn't make it very clear that we
> need to be able to break it apart into two separate queries, one of
> which will be run once and one of which will be iterated.

Perhaps because one could have multiple UNIONs.

> It's not a problem if UNION ALL is used within the initial_query and
> it's not a problem if UNION ALL is used within the iterated_query. But
> you can't apply ORDER BY to the result of the UNION, because the UNION
> is kind of fake -- we're not running the UNION as a single query,
> we're running the two halves separately, the first once and the second
> as many times as needed.

Even in the UNION ALL case there's still iteration.  Either the internal
table used to hold the CTE's rows has to be kept in order as rows are
added or it has to be sorted when the CTE query completes.

I see ORDER BY in a recursive query more as either a hint for creating
an internal index on the CTE, or a request to sort the CTE when the
recursive query completes (or as it goes even).

Something I wish were possible is to have indices on CTEs so they can
function more like temp tables that don't need to touch the pg_catalog.
Or maybe the optimizer can create indices on CTEs automatically based on
how the CTEs are used.

Speaking of CTEs as temp tables, GLOBAL TEMP tables would be nice.

Nico
-- 





^ permalink  raw  reply  [nested|flat] 214+ messages in thread

* Re: Remove restrictions in recursive query
  2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
@ 2025-03-27 17:00 ` David G. Johnston <[email protected]>
  1 sibling, 0 replies; 214+ messages in thread

From: David G. Johnston @ 2025-03-27 17:00 UTC (permalink / raw)
  To: Renan Alves Fonseca <[email protected]>; +Cc: pgsql-hackers

On Thu, Mar 27, 2025 at 9:02 AM Renan Alves Fonseca <[email protected]>
wrote:

> So, do we support the ORDER BY in a recursive query or not?
>

Apparently we do.  The "in" recurses.

If the answer is yes, I suggest one of the following modifications:
>
1. Change the error message to something like "ORDER BY at the top level of
> a recursive query is not implemented. HINT: wrap the respective statement
> around ()"
>

The error message is now correct but I'd lose the hint.  It assumes a typo
and that the query author meant to sort each iteration of the recursive
term; when maybe they did wish for the final result of the completed
recursive query to then be fed into a sort node and ordered, in which case
the parentheses wouldn't help.

David J.


^ permalink  raw  reply  [nested|flat] 214+ messages in thread


end of thread, other threads:[~2025-03-28 18:59 UTC | newest]

Thread overview: 214+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v29 3/6] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v30 3/6] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v31 3/6] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v35 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v32 3/6] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v34 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v32 3/6] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v39] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v40 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v38] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2025-03-27 16:02 Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
2025-03-27 16:37 ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
2025-03-27 16:39   ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
2025-03-27 18:03   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
2025-03-27 18:09     ` Re: Remove restrictions in recursive query David G. Johnston <[email protected]>
2025-03-27 18:21       ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
2025-03-27 18:32         ` Re: Remove restrictions in recursive query Robert Haas <[email protected]>
2025-03-27 21:21           ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
2025-03-27 21:50             ` Re: Remove restrictions in recursive query Tom Lane <[email protected]>
2025-03-27 22:29               ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
2025-03-28 00:14                 ` Re: Remove restrictions in recursive query Tom Lane <[email protected]>
2025-03-28 18:42                   ` Re: Remove restrictions in recursive query Renan Alves Fonseca <[email protected]>
2025-03-27 21:17         ` Re: Remove restrictions in recursive query Tom Lane <[email protected]>
2025-03-28 18:59   ` Re: Remove restrictions in recursive query Nico Williams <[email protected]>
2025-03-27 17:00 ` Re: Remove restrictions in recursive query David G. Johnston <[email protected]>

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