Subject: [PATCH v5] SQL-standard function body

From: Peter Eisentraut <[email-masked]>
Date: Tue, 27 Oct 2020 14:40:14 +0100

This adds support for writing CREATE FUNCTION and CREATE PROCEDURE
statements for language SQL with a function body that conforms to the
SQL standard and is portable to other implementations.

Instead of the PostgreSQL-specific AS $$ string literal $$ syntax,
this allows writing out the SQL statements making up the body
unquoted, either as a single statement:

    CREATE FUNCTION add(a integer, b integer) RETURNS integer
        LANGUAGE SQL
        RETURN a + b;

or as a block

    CREATE PROCEDURE insert_data(a integer, b integer)
    LANGUAGE SQL
    BEGIN ATOMIC
      INSERT INTO tbl VALUES (a);
      INSERT INTO tbl VALUES (b);
    END;

The function body is parsed at function definition time and stored as
expression nodes in a new pg_proc column prosqlbody.  So at run time,
no further parsing is required.

However, this form does not support polymorphic arguments, because
there is no more parse analysis done at call time.

Dependencies between the function and the objects it uses are fully
tracked.

A new RETURN statement is introduced.  This can only be used inside
function bodies.  Internally, it is treated much like a SELECT
statement.

psql needs some new intelligence to keep track of function body
boundaries so that it doesn't send off statements when it sees
semicolons that are inside a function body.

Also, per SQL standard, LANGUAGE SQL is the default, so it does not
need to be specified anymore.

Discussion: https://www.postgresql.org/message-id/flat/[email-masked]
---
 doc/src/sgml/catalogs.sgml                    |  10 +
 doc/src/sgml/ref/create_function.sgml         | 126 +++++++++--
 doc/src/sgml/ref/create_procedure.sgml        |  62 ++++-
 src/backend/catalog/pg_aggregate.c            |   1 +
 src/backend/catalog/pg_proc.c                 | 116 ++++++----
 src/backend/commands/aggregatecmds.c          |   2 +
 src/backend/commands/functioncmds.c           | 119 ++++++++--
 src/backend/commands/typecmds.c               |   1 +
 src/backend/executor/functions.c              |  79 ++++---
 src/backend/nodes/copyfuncs.c                 |  15 ++
 src/backend/nodes/equalfuncs.c                |  13 ++
 src/backend/nodes/outfuncs.c                  |  12 +
 src/backend/nodes/readfuncs.c                 |   1 +
 src/backend/optimizer/util/clauses.c          | 126 +++++++----
 src/backend/parser/analyze.c                  |  35 +++
 src/backend/parser/gram.y                     | 129 ++++++++---
 src/backend/tcop/postgres.c                   |   3 +-
 src/backend/utils/adt/ruleutils.c             | 106 ++++++++-
 src/bin/pg_dump/pg_dump.c                     |  45 +++-
 src/bin/psql/describe.c                       |  15 +-
 src/fe_utils/psqlscan.l                       |  23 +-
 src/include/catalog/pg_proc.dat               |   4 +
 src/include/catalog/pg_proc.h                 |   6 +-
 src/include/commands/defrem.h                 |   2 +
 src/include/executor/functions.h              |  15 ++
 src/include/fe_utils/psqlscan_int.h           |   2 +
 src/include/nodes/nodes.h                     |   1 +
 src/include/nodes/parsenodes.h                |  13 ++
 src/include/parser/kwlist.h                   |   2 +
 src/include/tcop/tcopprot.h                   |   1 +
 src/interfaces/ecpg/preproc/ecpg.addons       |   6 +
 src/interfaces/ecpg/preproc/ecpg.trailer      |   4 +-
 .../regress/expected/create_function_3.out    | 212 +++++++++++++++++-
 .../regress/expected/create_procedure.out     |  58 +++++
 src/test/regress/sql/create_function_3.sql    |  99 ++++++++
 src/test/regress/sql/create_procedure.sql     |  26 +++
 36 files changed, 1286 insertions(+), 204 deletions(-)

diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 5bd54cb218..a8ae9594e6 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -5972,6 +5972,16 @@ <title><structname>pg_proc</structname> Columns</title>
       </para></entry>
      </row>
 
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>prosqlbody</structfield> <type>pg_node_tree</type>
+      </para>
+      <para>
+       Pre-parsed SQL function body.  This will be used for language SQL
+       functions if the body is not specified as a string constant.
+       </para></entry>
+     </row>
+
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>proconfig</structfield> <type>text[]</type>
diff --git a/doc/src/sgml/ref/create_function.sgml b/doc/src/sgml/ref/create_function.sgml
index 3c1eaea651..1b5b9420db 100644
--- a/doc/src/sgml/ref/create_function.sgml
+++ b/doc/src/sgml/ref/create_function.sgml
@@ -38,6 +38,7 @@
     | SET <replaceable class="parameter">configuration_parameter</replaceable> { TO <replaceable class="parameter">value</replaceable> | = <replaceable class="parameter">value</replaceable> | FROM CURRENT }
     | AS '<replaceable class="parameter">definition</replaceable>'
     | AS '<replaceable class="parameter">obj_file</replaceable>', '<replaceable class="parameter">link_symbol</replaceable>'
+    | <replaceable class="parameter">sql_body</replaceable>
   } ...
 </synopsis>
  </refsynopsisdiv>
@@ -257,8 +258,9 @@ <title>Parameters</title>
        The name of the language that the function is implemented in.
        It can be <literal>sql</literal>, <literal>c</literal>,
        <literal>internal</literal>, or the name of a user-defined
-       procedural language, e.g., <literal>plpgsql</literal>.  Enclosing the
-       name in single quotes is deprecated and requires matching case.
+       procedural language, e.g., <literal>plpgsql</literal>.  The default is
+       <literal>sql</literal>.  Enclosing the name in single quotes is
+       deprecated and requires matching case.
       </para>
      </listitem>
     </varlistentry>
@@ -577,6 +579,44 @@ <title>Parameters</title>
      </listitem>
     </varlistentry>
 
+    <varlistentry>
+     <term><replaceable class="parameter">sql_body</replaceable></term>
+
+     <listitem>
+      <para>
+       The body of a <literal>LANGUAGE SQL</literal> function.  This can
+       either be a single statement
+<programlisting>
+RETURN <replaceable>expression</replaceable>
+</programlisting>
+       or a block
+<programlisting>
+BEGIN ATOMIC
+  <replaceable>statement</replaceable>;
+  <replaceable>statement</replaceable>;
+  ...
+  <replaceable>statement</replaceable>;
+END
+</programlisting>
+      </para>
+
+      <para>
+       This is similar to writing the text of the function body as a string
+       constant (see <replaceable>definition</replaceable> above), but there
+       are some differences: This form only works for <literal>LANGUAGE
+       SQL</literal>, the string constant form works for all languages.  This
+       form is parsed at function definition time, the string constant form is
+       parsed at execution time; therefore this form cannot support
+       polymorphic argument types and other constructs that are not resolvable
+       at function definition time.  This form tracks dependencies between the
+       function and objects used in the function body, so <literal>DROP
+       ... CASCADE</literal> will work correctly, whereas the form using
+       string literals may leave dangling functions.  Finally, this form is
+       more compatible with the SQL standard and other SQL implementations.
+      </para>
+     </listitem>
+    </varlistentry>
+
    </variablelist>
 
    <para>
@@ -669,6 +709,15 @@ <title>Examples</title>
     LANGUAGE SQL
     IMMUTABLE
     RETURNS NULL ON NULL INPUT;
+</programlisting>
+   The same function written in a more SQL-conforming style, using argument
+   names and an unquoted body:
+<programlisting>
+CREATE FUNCTION add(a integer, b integer) RETURNS integer
+    LANGUAGE SQL
+    IMMUTABLE
+    RETURNS NULL ON NULL INPUT
+    RETURN a + b;
 </programlisting>
   </para>
 
@@ -799,23 +848,74 @@ <title>Writing <literal>SECURITY DEFINER</literal> Functions Safely</title>
   <title>Compatibility</title>
 
   <para>
-   A <command>CREATE FUNCTION</command> command is defined in the SQL standard.
-   The <productname>PostgreSQL</productname> version is similar but
-   not fully compatible.  The attributes are not portable, neither are the
-   different available languages.
+   A <command>CREATE FUNCTION</command> command is defined in the SQL
+   standard.  The <productname>PostgreSQL</productname> implementation can be
+   used in a compatible way but has many extensions.  Conversely, the SQL
+   standard specifies a number of optional features that are not implemented
+   in <productname>PostgreSQL</productname>.
   </para>
 
   <para>
-   For compatibility with some other database systems,
-   <replaceable class="parameter">argmode</replaceable> can be written
-   either before or after <replaceable class="parameter">argname</replaceable>.
-   But only the first way is standard-compliant.
+   The following are important compatibility issues:
+
+   <itemizedlist>
+    <listitem>
+     <para>
+      <literal>OR REPLACE</literal> is a PostgreSQL extension.
+     </para>
+    </listitem>
+
+    <listitem>
+     <para>
+      For compatibility with some other database systems, <replaceable
+      class="parameter">argmode</replaceable> can be written either before or
+      after <replaceable class="parameter">argname</replaceable>.  But only
+      the first way is standard-compliant.
+     </para>
+    </listitem>
+
+    <listitem>
+     <para>
+      For parameter defaults, the SQL standard specifies only the syntax with
+      the <literal>DEFAULT</literal> key word.  The syntax with
+      <literal>=</literal> is used in T-SQL and Firebird.
+     </para>
+    </listitem>
+
+    <listitem>
+     <para>
+      The <literal>SETOF</literal> modifier is a PostgreSQL extension.
+     </para>
+    </listitem>
+
+    <listitem>
+     <para>
+      Only <literal>SQL</literal> is standardized as a language.
+     </para>
+    </listitem>
+
+    <listitem>
+     <para>
+      All other attributes except <literal>CALLED ON NULL INPUT</literal> and
+      <literal>RETURNS NULL ON NULL INPUT</literal> are not standardized.
+     </para>
+    </listitem>
+
+    <listitem>
+     <para>
+      For the body of <literal>LANGUAGE SQL</literal> functions, the SQL
+      standard only specifies the <replaceable>sql_body</replaceable> form.
+     </para>
+    </listitem>
+   </itemizedlist>
   </para>
 
   <para>
-   For parameter defaults, the SQL standard specifies only the syntax with
-   the <literal>DEFAULT</literal> key word.  The syntax
-   with <literal>=</literal> is used in T-SQL and Firebird.
+   Simple <literal>LANGUAGE SQL</literal> functions can be written in a way
+   that is both standard-conforming and portable to other implementations.
+   More complex functions using advanced features, optimization attributes, or
+   other languages will necessarily be specific to PostgreSQL in a significant
+   way.
   </para>
  </refsect1>
 
diff --git a/doc/src/sgml/ref/create_procedure.sgml b/doc/src/sgml/ref/create_procedure.sgml
index e258eca5ce..ecdeac1629 100644
--- a/doc/src/sgml/ref/create_procedure.sgml
+++ b/doc/src/sgml/ref/create_procedure.sgml
@@ -29,6 +29,7 @@
     | SET <replaceable class="parameter">configuration_parameter</replaceable> { TO <replaceable class="parameter">value</replaceable> | = <replaceable class="parameter">value</replaceable> | FROM CURRENT }
     | AS '<replaceable class="parameter">definition</replaceable>'
     | AS '<replaceable class="parameter">obj_file</replaceable>', '<replaceable class="parameter">link_symbol</replaceable>'
+    | <replaceable class="parameter">sql_body</replaceable>
   } ...
 </synopsis>
  </refsynopsisdiv>
@@ -162,8 +163,9 @@ <title>Parameters</title>
        The name of the language that the procedure is implemented in.
        It can be <literal>sql</literal>, <literal>c</literal>,
        <literal>internal</literal>, or the name of a user-defined
-       procedural language, e.g., <literal>plpgsql</literal>.  Enclosing the
-       name in single quotes is deprecated and requires matching case.
+       procedural language, e.g., <literal>plpgsql</literal>.  The default is
+       <literal>sql</literal>.  Enclosing the name in single quotes is
+       deprecated and requires matching case.
       </para>
      </listitem>
     </varlistentry>
@@ -299,6 +301,41 @@ <title>Parameters</title>
 
      </listitem>
     </varlistentry>
+
+    <varlistentry>
+     <term><replaceable class="parameter">sql_body</replaceable></term>
+
+     <listitem>
+      <para>
+       The body of a <literal>LANGUAGE SQL</literal> procedure.  This should
+       be a block
+<programlisting>
+BEGIN ATOMIC
+  <replaceable>statement</replaceable>;
+  <replaceable>statement</replaceable>;
+  ...
+  <replaceable>statement</replaceable>;
+END
+</programlisting>
+      </para>
+
+      <para>
+       This is similar to writing the text of the procedure body as a string
+       constant (see <replaceable>definition</replaceable> above), but there
+       are some differences: This form only works for <literal>LANGUAGE
+       SQL</literal>, the string constant form works for all languages.  This
+       form is parsed at procedure definition time, the string constant form is
+       parsed at execution time; therefore this form cannot support
+       polymorphic argument types and other constructs that are not resolvable
+       at procedure definition time.  This form tracks dependencies between the
+       procedure and objects used in the procedure body, so <literal>DROP
+       ... CASCADE</literal> will work correctly, whereas the form using
+       string literals may leave dangling procedures.  Finally, this form is
+       more compatible with the SQL standard and other SQL implementations.
+      </para>
+     </listitem>
+    </varlistentry>
+
    </variablelist>
  </refsect1>
 
@@ -318,6 +355,7 @@ <title>Notes</title>
  <refsect1 id="sql-createprocedure-examples">
   <title>Examples</title>
 
+  <para>
 <programlisting>
 CREATE PROCEDURE insert_data(a integer, b integer)
 LANGUAGE SQL
@@ -325,9 +363,21 @@ <title>Examples</title>
 INSERT INTO tbl VALUES (a);
 INSERT INTO tbl VALUES (b);
 $$;
-
+</programlisting>
+   or
+<programlisting>
+CREATE PROCEDURE insert_data(a integer, b integer)
+LANGUAGE SQL
+BEGIN ATOMIC
+  INSERT INTO tbl VALUES (a);
+  INSERT INTO tbl VALUES (b);
+END;
+</programlisting>
+   and call like this:
+<programlisting>
 CALL insert_data(1, 2);
 </programlisting>
+  </para>
  </refsect1>
 
  <refsect1 id="sql-createprocedure-compat">
@@ -335,9 +385,9 @@ <title>Compatibility</title>
 
   <para>
    A <command>CREATE PROCEDURE</command> command is defined in the SQL
-   standard.  The <productname>PostgreSQL</productname> version is similar but
-   not fully compatible.  For details see
-   also <xref linkend="sql-createfunction"/>.
+   standard.  The <productname>PostgreSQL</productname> implementation can be
+   used in a compatible way but has many extensions.  For details see also
+   <xref linkend="sql-createfunction"/>.
   </para>
  </refsect1>
 
diff --git a/src/backend/catalog/pg_aggregate.c b/src/backend/catalog/pg_aggregate.c
index 0cf1da6ebb..9d6032bf88 100644
--- a/src/backend/catalog/pg_aggregate.c
+++ b/src/backend/catalog/pg_aggregate.c
@@ -622,6 +622,7 @@ AggregateCreate(const char *aggName,
 							 InvalidOid,	/* no validator */
 							 "aggregate_dummy", /* placeholder proc */
 							 NULL,	/* probin */
+							 NULL,	/* prosqlbody */
 							 PROKIND_AGGREGATE,
 							 false, /* security invoker (currently not
 									 * definable for agg) */
diff --git a/src/backend/catalog/pg_proc.c b/src/backend/catalog/pg_proc.c
index 1dd9ecc063..808d48949a 100644
--- a/src/backend/catalog/pg_proc.c
+++ b/src/backend/catalog/pg_proc.c
@@ -32,6 +32,7 @@
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/nodeFuncs.h"
+#include "parser/analyze.h"
 #include "parser/parse_coerce.h"
 #include "parser/parse_type.h"
 #include "tcop/pquery.h"
@@ -76,6 +77,7 @@ ProcedureCreate(const char *procedureName,
 				Oid languageValidator,
 				const char *prosrc,
 				const char *probin,
+				Node *prosqlbody,
 				char prokind,
 				bool security_definer,
 				bool isLeakProof,
@@ -119,8 +121,6 @@ ProcedureCreate(const char *procedureName,
 	/*
 	 * sanity checks
 	 */
-	Assert(PointerIsValid(prosrc));
-
 	parameterCount = parameterTypes->dim1;
 	if (parameterCount < 0 || parameterCount > FUNC_MAX_ARGS)
 		ereport(ERROR,
@@ -334,11 +334,18 @@ ProcedureCreate(const char *procedureName,
 		values[Anum_pg_proc_protrftypes - 1] = trftypes;
 	else
 		nulls[Anum_pg_proc_protrftypes - 1] = true;
-	values[Anum_pg_proc_prosrc - 1] = CStringGetTextDatum(prosrc);
+	if (prosrc)
+		values[Anum_pg_proc_prosrc - 1] = CStringGetTextDatum(prosrc);
+	else
+		nulls[Anum_pg_proc_prosrc - 1] = true;
 	if (probin)
 		values[Anum_pg_proc_probin - 1] = CStringGetTextDatum(probin);
 	else
 		nulls[Anum_pg_proc_probin - 1] = true;
+	if (prosqlbody)
+		values[Anum_pg_proc_prosqlbody - 1] = CStringGetTextDatum(nodeToString(prosqlbody));
+	else
+		nulls[Anum_pg_proc_prosqlbody - 1] = true;
 	if (proconfig != PointerGetDatum(NULL))
 		values[Anum_pg_proc_proconfig - 1] = proconfig;
 	else
@@ -638,6 +645,10 @@ ProcedureCreate(const char *procedureName,
 	record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
 	free_object_addresses(addrs);
 
+	/* dependency on SQL routine body */
+	if (languageObjectId == SQLlanguageId && prosqlbody)
+		recordDependencyOnExpr(&myself, prosqlbody, NIL, DEPENDENCY_NORMAL);
+
 	/* dependency on parameter default expressions */
 	if (parameterDefaults)
 		recordDependencyOnExpr(&myself, (Node *) parameterDefaults,
@@ -861,61 +872,81 @@ fmgr_sql_validator(PG_FUNCTION_ARGS)
 	/* Postpone body checks if !check_function_bodies */
 	if (check_function_bodies)
 	{
-		tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
-		if (isnull)
-			elog(ERROR, "null prosrc");
-
-		prosrc = TextDatumGetCString(tmp);
-
 		/*
 		 * Setup error traceback support for ereport().
 		 */
 		callback_arg.proname = NameStr(proc->proname);
-		callback_arg.prosrc = prosrc;
+		callback_arg.prosrc = NULL;
 
 		sqlerrcontext.callback = sql_function_parse_error_callback;
 		sqlerrcontext.arg = (void *) &callback_arg;
 		sqlerrcontext.previous = error_context_stack;
 		error_context_stack = &sqlerrcontext;
 
-		/*
-		 * We can't do full prechecking of the function definition if there
-		 * are any polymorphic input types, because actual datatypes of
-		 * expression results will be unresolvable.  The check will be done at
-		 * runtime instead.
-		 *
-		 * We can run the text through the raw parser though; this will at
-		 * least catch silly syntactic errors.
-		 */
-		raw_parsetree_list = pg_parse_query(prosrc);
+		tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
+		if (isnull)
+		{
+			Node	   *n;
 
-		if (!haspolyarg)
+			tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosqlbody, &isnull);
+			if (isnull)
+				elog(ERROR, "null prosrc and prosqlbody");
+
+			n = stringToNode(TextDatumGetCString(tmp));
+			if (IsA(n, List))
+				querytree_list = castNode(List, n);
+			else
+				querytree_list = list_make1(list_make1(n));
+		}
+		else
 		{
+			prosrc = TextDatumGetCString(tmp);
+
+			callback_arg.prosrc = prosrc;
+
 			/*
-			 * OK to do full precheck: analyze and rewrite the queries, then
-			 * verify the result type.
+			 * We can't do full prechecking of the function definition if there
+			 * are any polymorphic input types, because actual datatypes of
+			 * expression results will be unresolvable.  The check will be done at
+			 * runtime instead.
+			 *
+			 * We can run the text through the raw parser though; this will at
+			 * least catch silly syntactic errors.
 			 */
-			SQLFunctionParseInfoPtr pinfo;
-			Oid			rettype;
-			TupleDesc	rettupdesc;
+			raw_parsetree_list = pg_parse_query(prosrc);
 
-			/* But first, set up parameter information */
-			pinfo = prepare_sql_fn_parse_info(tuple, NULL, InvalidOid);
-
-			querytree_list = NIL;
-			foreach(lc, raw_parsetree_list)
+			if (!haspolyarg)
 			{
-				RawStmt    *parsetree = lfirst_node(RawStmt, lc);
-				List	   *querytree_sublist;
-
-				querytree_sublist = pg_analyze_and_rewrite_params(parsetree,
-																  prosrc,
-																  (ParserSetupHook) sql_fn_parser_setup,
-																  pinfo,
-																  NULL);
-				querytree_list = lappend(querytree_list,
-										 querytree_sublist);
+				/*
+				 * OK to do full precheck: analyze and rewrite the queries, then
+				 * verify the result type.
+				 */
+				SQLFunctionParseInfoPtr pinfo;
+
+				/* But first, set up parameter information */
+				pinfo = prepare_sql_fn_parse_info(tuple, NULL, InvalidOid);
+
+				querytree_list = NIL;
+				foreach(lc, raw_parsetree_list)
+				{
+					RawStmt    *parsetree = lfirst_node(RawStmt, lc);
+					List	   *querytree_sublist;
+
+					querytree_sublist = pg_analyze_and_rewrite_params(parsetree,
+																	  prosrc,
+																	  (ParserSetupHook) sql_fn_parser_setup,
+																	  pinfo,
+																	  NULL);
+					querytree_list = lappend(querytree_list,
+											 querytree_sublist);
+				}
 			}
+		}
+
+		if (!haspolyarg)
+		{
+			Oid			rettype;
+			TupleDesc	rettupdesc;
 
 			check_sql_fn_statements(querytree_list);
 
@@ -968,6 +999,9 @@ function_parse_error_transpose(const char *prosrc)
 	int			newerrposition;
 	const char *queryText;
 
+	if (!prosrc)
+		return false;
+
 	/*
 	 * Nothing to do unless we are dealing with a syntax error that has a
 	 * cursor position.
diff --git a/src/backend/commands/aggregatecmds.c b/src/backend/commands/aggregatecmds.c
index 6bf54e64f8..26b3fa27de 100644
--- a/src/backend/commands/aggregatecmds.c
+++ b/src/backend/commands/aggregatecmds.c
@@ -313,9 +313,11 @@ DefineAggregate(ParseState *pstate,
 										  InvalidOid,
 										  OBJECT_AGGREGATE,
 										  &parameterTypes,
+										  NULL,
 										  &allParameterTypes,
 										  &parameterModes,
 										  &parameterNames,
+										  NULL,
 										  &parameterDefaults,
 										  &variadicArgType,
 										  &requiredResultType);
diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index c3ce480c8f..c48d3744a4 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -53,9 +53,11 @@
 #include "commands/proclang.h"
 #include "executor/execdesc.h"
 #include "executor/executor.h"
+#include "executor/functions.h"
 #include "funcapi.h"
 #include "miscadmin.h"
 #include "optimizer/optimizer.h"
+#include "parser/analyze.h"
 #include "parser/parse_coerce.h"
 #include "parser/parse_collate.h"
 #include "parser/parse_expr.h"
@@ -186,9 +188,11 @@ interpret_function_parameter_list(ParseState *pstate,
 								  Oid languageOid,
 								  ObjectType objtype,
 								  oidvector **parameterTypes,
+								  List **parameterTypes_list,
 								  ArrayType **allParameterTypes,
 								  ArrayType **parameterModes,
 								  ArrayType **parameterNames,
+								  List **inParameterNames_list,
 								  List **parameterDefaults,
 								  Oid *variadicArgType,
 								  Oid *requiredResultType)
@@ -283,7 +287,11 @@ interpret_function_parameter_list(ParseState *pstate,
 
 		/* handle input parameters */
 		if (fp->mode != FUNC_PARAM_OUT && fp->mode != FUNC_PARAM_TABLE)
+		{
 			isinput = true;
+			if (parameterTypes_list)
+				*parameterTypes_list = lappend_oid(*parameterTypes_list, toid);
+		}
 
 		/* handle signature parameters */
 		if (fp->mode == FUNC_PARAM_IN || fp->mode == FUNC_PARAM_INOUT ||
@@ -372,6 +380,9 @@ interpret_function_parameter_list(ParseState *pstate,
 			have_names = true;
 		}
 
+		if (inParameterNames_list)
+			*inParameterNames_list = lappend(*inParameterNames_list, makeString(fp->name ? fp->name : pstrdup("")));
+
 		if (fp->defexpr)
 		{
 			Node	   *def;
@@ -786,28 +797,10 @@ compute_function_attributes(ParseState *pstate,
 				 defel->defname);
 	}
 
-	/* process required items */
 	if (as_item)
 		*as = (List *) as_item->arg;
-	else
-	{
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
-				 errmsg("no function body specified")));
-		*as = NIL;				/* keep compiler quiet */
-	}
-
 	if (language_item)
 		*language = strVal(language_item->arg);
-	else
-	{
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
-				 errmsg("no language specified")));
-		*language = NULL;		/* keep compiler quiet */
-	}
-
-	/* process optional items */
 	if (transform_item)
 		*transform = transform_item->arg;
 	if (windowfunc_item)
@@ -856,10 +849,21 @@ compute_function_attributes(ParseState *pstate,
  */
 static void
 interpret_AS_clause(Oid languageOid, const char *languageName,
-					char *funcname, List *as,
-					char **prosrc_str_p, char **probin_str_p)
+					char *funcname, List *as, Node *sql_body_in,
+					List *parameterTypes, List *inParameterNames,
+					char **prosrc_str_p, char **probin_str_p, Node **sql_body_out)
 {
-	Assert(as != NIL);
+	if (sql_body_in && as)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
+				 errmsg("duplicate function body specified")));
+
+	if (sql_body_in && languageOid != SQLlanguageId)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
+				 errmsg("inline SQL function body only valid for language SQL")));
+
+	*sql_body_out = NULL;
 
 	if (languageOid == ClanguageId)
 	{
@@ -881,6 +885,66 @@ interpret_AS_clause(Oid languageOid, const char *languageName,
 				*prosrc_str_p = funcname;
 		}
 	}
+	else if (sql_body_in)
+	{
+		SQLFunctionParseInfoPtr pinfo;
+
+		pinfo = (SQLFunctionParseInfoPtr) palloc0(sizeof(SQLFunctionParseInfo));
+
+		pinfo->fname = funcname;
+		pinfo->nargs = list_length(parameterTypes);
+		pinfo->argtypes = (Oid *) palloc(pinfo->nargs * sizeof(Oid));
+		pinfo->argnames = (char **) palloc(pinfo->nargs * sizeof(char *));
+		for (int i = 0; i < list_length(parameterTypes); i++)
+		{
+			char *s = strVal(list_nth(inParameterNames, i));
+
+			pinfo->argtypes[i] = list_nth_oid(parameterTypes, i);
+			if (IsPolymorphicType(pinfo->argtypes[i]))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
+						 errmsg("SQL function with unquoted function body cannot have polymorphic arguments")));
+
+			if (s[0] != '\0')
+				pinfo->argnames[i] = s;
+			else
+				pinfo->argnames[i] = NULL;
+		}
+
+		if (IsA(sql_body_in, List))
+		{
+			List	   *stmts = linitial_node(List, castNode(List, sql_body_in));
+			ListCell   *lc;
+			List	   *transformed_stmts = NIL;
+
+			foreach(lc, stmts)
+			{
+				Node	   *stmt = lfirst(lc);
+				Query	   *q;
+				ParseState *pstate = make_parsestate(NULL);
+
+				sql_fn_parser_setup(pstate, pinfo);
+				q = transformStmt(pstate, stmt);
+				transformed_stmts = lappend(transformed_stmts, q);
+				free_parsestate(pstate);
+			}
+
+			*sql_body_out = (Node *) list_make1(transformed_stmts);
+		}
+		else
+		{
+			Query	   *q;
+			ParseState *pstate = make_parsestate(NULL);
+
+			sql_fn_parser_setup(pstate, pinfo);
+			q = transformStmt(pstate, sql_body_in);
+
+			*sql_body_out = (Node *) q;
+		}
+
+		*probin_str_p = NULL;
+		*prosrc_str_p = NULL;
+	}
 	else
 	{
 		/* Everything else wants the given string in prosrc. */
@@ -919,6 +983,7 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
 {
 	char	   *probin_str;
 	char	   *prosrc_str;
+	Node	   *prosqlbody;
 	Oid			prorettype;
 	bool		returnsSet;
 	char	   *language;
@@ -929,9 +994,11 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
 	Oid			namespaceId;
 	AclResult	aclresult;
 	oidvector  *parameterTypes;
+	List	   *parameterTypes_list = NIL;
 	ArrayType  *allParameterTypes;
 	ArrayType  *parameterModes;
 	ArrayType  *parameterNames;
+	List	   *inParameterNames_list = NIL;
 	List	   *parameterDefaults;
 	Oid			variadicArgType;
 	List	   *trftypes_list = NIL;
@@ -962,6 +1029,8 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
 					   get_namespace_name(namespaceId));
 
 	/* Set default attributes */
+	as_clause = NULL;
+	language = "sql";
 	isWindowFunc = false;
 	isStrict = false;
 	security = false;
@@ -1053,9 +1122,11 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
 									  languageOid,
 									  stmt->is_procedure ? OBJECT_PROCEDURE : OBJECT_FUNCTION,
 									  &parameterTypes,
+									  &parameterTypes_list,
 									  &allParameterTypes,
 									  &parameterModes,
 									  &parameterNames,
+									  &inParameterNames_list,
 									  &parameterDefaults,
 									  &variadicArgType,
 									  &requiredResultType);
@@ -1112,8 +1183,9 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
 		trftypes = NULL;
 	}
 
-	interpret_AS_clause(languageOid, language, funcname, as_clause,
-						&prosrc_str, &probin_str);
+	interpret_AS_clause(languageOid, language, funcname, as_clause, stmt->sql_body,
+						parameterTypes_list, inParameterNames_list,
+						&prosrc_str, &probin_str, &prosqlbody);
 
 	/*
 	 * Set default values for COST and ROWS depending on other parameters;
@@ -1155,6 +1227,7 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
 						   languageValidator,
 						   prosrc_str,	/* converted to text later */
 						   probin_str,	/* converted to text later */
+						   prosqlbody,
 						   stmt->is_procedure ? PROKIND_PROCEDURE : (isWindowFunc ? PROKIND_WINDOW : PROKIND_FUNCTION),
 						   security,
 						   isLeakProof,
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 483bb65ddc..65aa91d80f 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -1588,6 +1588,7 @@ makeRangeConstructors(const char *name, Oid namespace,
 								 F_FMGR_INTERNAL_VALIDATOR, /* language validator */
 								 prosrc[i], /* prosrc */
 								 NULL,	/* probin */
+								 NULL,	/* prosqlbody */
 								 PROKIND_FUNCTION,
 								 false, /* security_definer */
 								 false, /* leakproof */
diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c
index 459a33375b..3ca7e89d44 100644
--- a/src/backend/executor/functions.c
+++ b/src/backend/executor/functions.c
@@ -26,6 +26,7 @@
 #include "parser/parse_coerce.h"
 #include "parser/parse_collate.h"
 #include "parser/parse_func.h"
+#include "rewrite/rewriteHandler.h"
 #include "storage/proc.h"
 #include "tcop/utility.h"
 #include "utils/builtins.h"
@@ -128,21 +129,6 @@ typedef struct
 
 typedef SQLFunctionCache *SQLFunctionCachePtr;
 
-/*
- * Data structure needed by the parser callback hooks to resolve parameter
- * references during parsing of a SQL function's body.  This is separate from
- * SQLFunctionCache since we sometimes do parsing separately from execution.
- */
-typedef struct SQLFunctionParseInfo
-{
-	char	   *fname;			/* function's name */
-	int			nargs;			/* number of input arguments */
-	Oid		   *argtypes;		/* resolved types of input arguments */
-	char	  **argnames;		/* names of input arguments; NULL if none */
-	/* Note that argnames[i] can be NULL, if some args are unnamed */
-	Oid			collation;		/* function's input collation, if known */
-}			SQLFunctionParseInfo;
-
 
 /* non-export function prototypes */
 static Node *sql_fn_param_ref(ParseState *pstate, ParamRef *pref);
@@ -607,7 +593,6 @@ init_sql_fcache(FunctionCallInfo fcinfo, Oid collation, bool lazyEvalOK)
 	HeapTuple	procedureTuple;
 	Form_pg_proc procedureStruct;
 	SQLFunctionCachePtr fcache;
-	List	   *raw_parsetree_list;
 	List	   *queryTree_list;
 	List	   *resulttlist;
 	ListCell   *lc;
@@ -682,9 +667,6 @@ init_sql_fcache(FunctionCallInfo fcinfo, Oid collation, bool lazyEvalOK)
 						  procedureTuple,
 						  Anum_pg_proc_prosrc,
 						  &isNull);
-	if (isNull)
-		elog(ERROR, "null prosrc for function %u", foid);
-	fcache->src = TextDatumGetCString(tmp);
 
 	/*
 	 * Parse and rewrite the queries in the function text.  Use sublists to
@@ -695,20 +677,55 @@ init_sql_fcache(FunctionCallInfo fcinfo, Oid collation, bool lazyEvalOK)
 	 * but we'll not worry about it until the module is rewritten to use
 	 * plancache.c.
 	 */
-	raw_parsetree_list = pg_parse_query(fcache->src);
-
 	queryTree_list = NIL;
-	foreach(lc, raw_parsetree_list)
+	if (isNull)
 	{
-		RawStmt    *parsetree = lfirst_node(RawStmt, lc);
-		List	   *queryTree_sublist;
-
-		queryTree_sublist = pg_analyze_and_rewrite_params(parsetree,
-														  fcache->src,
-														  (ParserSetupHook) sql_fn_parser_setup,
-														  fcache->pinfo,
-														  NULL);
-		queryTree_list = lappend(queryTree_list, queryTree_sublist);
+		Node	   *n;
+		List	   *stored_query_list;
+
+		tmp = SysCacheGetAttr(PROCOID,
+							  procedureTuple,
+							  Anum_pg_proc_prosqlbody,
+							  &isNull);
+		if (isNull)
+			elog(ERROR, "null prosrc and prosqlbody for function %u", foid);
+
+		n = stringToNode(TextDatumGetCString(tmp));
+		if (IsA(n, List))
+			stored_query_list = linitial_node(List, castNode(List, n));
+		else
+			stored_query_list = list_make1(n);
+
+		foreach(lc, stored_query_list)
+		{
+			Query	   *parsetree = lfirst_node(Query, lc);
+			List	   *queryTree_sublist;
+
+			AcquireRewriteLocks(parsetree, true, false);
+			queryTree_sublist = pg_rewrite_query(parsetree);
+			queryTree_list = lappend(queryTree_list, queryTree_sublist);
+		}
+	}
+	else
+	{
+		List	   *raw_parsetree_list;
+
+		fcache->src = TextDatumGetCString(tmp);
+
+		raw_parsetree_list = pg_parse_query(fcache->src);
+
+		foreach(lc, raw_parsetree_list)
+		{
+			RawStmt    *parsetree = lfirst_node(RawStmt, lc);
+			List	   *queryTree_sublist;
+
+			queryTree_sublist = pg_analyze_and_rewrite_params(parsetree,
+															  fcache->src,
+															  (ParserSetupHook) sql_fn_parser_setup,
+															  fcache->pinfo,
+															  NULL);
+			queryTree_list = lappend(queryTree_list, queryTree_sublist);
+		}
 	}
 
 	/*
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 2b4d7654cc..b973b3b967 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -3067,6 +3067,7 @@ _copyQuery(const Query *from)
 	COPY_SCALAR_FIELD(hasModifyingCTE);
 	COPY_SCALAR_FIELD(hasForUpdate);
 	COPY_SCALAR_FIELD(hasRowSecurity);
+	COPY_SCALAR_FIELD(isReturn);
 	COPY_NODE_FIELD(cteList);
 	COPY_NODE_FIELD(rtable);
 	COPY_NODE_FIELD(jointree);
@@ -3195,6 +3196,16 @@ _copySetOperationStmt(const SetOperationStmt *from)
 	return newnode;
 }
 
+static ReturnStmt *
+_copyReturnStmt(const ReturnStmt *from)
+{
+	ReturnStmt *newnode = makeNode(ReturnStmt);
+
+	COPY_NODE_FIELD(returnval);
+
+	return newnode;
+}
+
 static AlterTableStmt *
 _copyAlterTableStmt(const AlterTableStmt *from)
 {
@@ -3571,6 +3582,7 @@ _copyCreateFunctionStmt(const CreateFunctionStmt *from)
 	COPY_NODE_FIELD(parameters);
 	COPY_NODE_FIELD(returnType);
 	COPY_NODE_FIELD(options);
+	COPY_NODE_FIELD(sql_body);
 
 	return newnode;
 }
@@ -5223,6 +5235,9 @@ copyObjectImpl(const void *from)
 		case T_SetOperationStmt:
 			retval = _copySetOperationStmt(from);
 			break;
+		case T_ReturnStmt:
+			retval = _copyReturnStmt(from);
+			break;
 		case T_AlterTableStmt:
 			retval = _copyAlterTableStmt(from);
 			break;
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index e2d1b987bf..0051b1a88b 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -966,6 +966,7 @@ _equalQuery(const Query *a, const Query *b)
 	COMPARE_SCALAR_FIELD(hasModifyingCTE);
 	COMPARE_SCALAR_FIELD(hasForUpdate);
 	COMPARE_SCALAR_FIELD(hasRowSecurity);
+	COMPARE_SCALAR_FIELD(isReturn);
 	COMPARE_NODE_FIELD(cteList);
 	COMPARE_NODE_FIELD(rtable);
 	COMPARE_NODE_FIELD(jointree);
@@ -1082,6 +1083,14 @@ _equalSetOperationStmt(const SetOperationStmt *a, const SetOperationStmt *b)
 	return true;
 }
 
+static bool
+_equalReturnStmt(const ReturnStmt *a, const ReturnStmt *b)
+{
+	COMPARE_NODE_FIELD(returnval);
+
+	return true;
+}
+
 static bool
 _equalAlterTableStmt(const AlterTableStmt *a, const AlterTableStmt *b)
 {
@@ -1394,6 +1403,7 @@ _equalCreateFunctionStmt(const CreateFunctionStmt *a, const CreateFunctionStmt *
 	COMPARE_NODE_FIELD(parameters);
 	COMPARE_NODE_FIELD(returnType);
 	COMPARE_NODE_FIELD(options);
+	COMPARE_NODE_FIELD(sql_body);
 
 	return true;
 }
@@ -3277,6 +3287,9 @@ equal(const void *a, const void *b)
 		case T_SetOperationStmt:
 			retval = _equalSetOperationStmt(a, b);
 			break;
+		case T_ReturnStmt:
+			retval = _equalReturnStmt(a, b);
+			break;
 		case T_AlterTableStmt:
 			retval = _equalAlterTableStmt(a, b);
 			break;
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 08a049232e..a03b97e7d2 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -2756,6 +2756,14 @@ _outSelectStmt(StringInfo str, const SelectStmt *node)
 	WRITE_NODE_FIELD(rarg);
 }
 
+static void
+_outReturnStmt(StringInfo str, const ReturnStmt *node)
+{
+	WRITE_NODE_TYPE("RETURN");
+
+	WRITE_NODE_FIELD(returnval);
+}
+
 static void
 _outFuncCall(StringInfo str, const FuncCall *node)
 {
@@ -2944,6 +2952,7 @@ _outQuery(StringInfo str, const Query *node)
 	WRITE_BOOL_FIELD(hasModifyingCTE);
 	WRITE_BOOL_FIELD(hasForUpdate);
 	WRITE_BOOL_FIELD(hasRowSecurity);
+	WRITE_BOOL_FIELD(isReturn);
 	WRITE_NODE_FIELD(cteList);
 	WRITE_NODE_FIELD(rtable);
 	WRITE_NODE_FIELD(jointree);
@@ -4194,6 +4203,9 @@ outNode(StringInfo str, const void *obj)
 			case T_SelectStmt:
 				_outSelectStmt(str, obj);
 				break;
+			case T_ReturnStmt:
+				_outReturnStmt(str, obj);
+				break;
 			case T_ColumnDef:
 				_outColumnDef(str, obj);
 				break;
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index ab7b535caa..d01746d0ee 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -263,6 +263,7 @@ _readQuery(void)
 	READ_BOOL_FIELD(hasModifyingCTE);
 	READ_BOOL_FIELD(hasForUpdate);
 	READ_BOOL_FIELD(hasRowSecurity);
+	READ_BOOL_FIELD(isReturn);
 	READ_NODE_FIELD(cteList);
 	READ_NODE_FIELD(rtable);
 	READ_NODE_FIELD(jointree);
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index e7d814651b..f9d27562c0 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -4416,27 +4416,47 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
 								  ALLOCSET_DEFAULT_SIZES);
 	oldcxt = MemoryContextSwitchTo(mycxt);
 
-	/* Fetch the function body */
-	tmp = SysCacheGetAttr(PROCOID,
-						  func_tuple,
-						  Anum_pg_proc_prosrc,
-						  &isNull);
-	if (isNull)
-		elog(ERROR, "null prosrc for function %u", funcid);
-	src = TextDatumGetCString(tmp);
-
 	/*
 	 * Setup error traceback support for ereport().  This is so that we can
 	 * finger the function that bad information came from.
 	 */
 	callback_arg.proname = NameStr(funcform->proname);
-	callback_arg.prosrc = src;
+	callback_arg.prosrc = NULL;
 
 	sqlerrcontext.callback = sql_inline_error_callback;
 	sqlerrcontext.arg = (void *) &callback_arg;
 	sqlerrcontext.previous = error_context_stack;
 	error_context_stack = &sqlerrcontext;
 
+	/* Fetch the function body */
+	tmp = SysCacheGetAttr(PROCOID,
+						  func_tuple,
+						  Anum_pg_proc_prosrc,
+						  &isNull);
+	if (isNull)
+	{
+		Node	   *n;
+		List	   *querytree_list;
+
+		tmp = SysCacheGetAttr(PROCOID, func_tuple, Anum_pg_proc_prosqlbody, &isNull);
+		if (isNull)
+			elog(ERROR, "null prosrc and prosqlbody for function %u", funcid);
+
+		n = stringToNode(TextDatumGetCString(tmp));
+		if (IsA(n, List))
+			querytree_list = linitial_node(List, castNode(List, n));
+		else
+			querytree_list = list_make1(n);
+		if (list_length(querytree_list) != 1)
+			goto fail;
+		querytree = linitial(querytree_list);
+	}
+	else
+	{
+	src = TextDatumGetCString(tmp);
+
+	callback_arg.prosrc = src;
+
 	/*
 	 * Set up to handle parameters while parsing the function body.  We need a
 	 * dummy FuncExpr node containing the already-simplified arguments to pass
@@ -4480,6 +4500,7 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
 	querytree = transformTopLevelStmt(pstate, linitial(raw_parsetree_list));
 
 	free_parsestate(pstate);
+	}
 
 	/*
 	 * The single command must be a simple "SELECT expression".
@@ -4736,12 +4757,15 @@ sql_inline_error_callback(void *arg)
 	int			syntaxerrposition;
 
 	/* If it's a syntax error, convert to internal syntax error report */
-	syntaxerrposition = geterrposition();
-	if (syntaxerrposition > 0)
+	if (callback_arg->prosrc)
 	{
-		errposition(0);
-		internalerrposition(syntaxerrposition);
-		internalerrquery(callback_arg->prosrc);
+		syntaxerrposition = geterrposition();
+		if (syntaxerrposition > 0)
+		{
+			errposition(0);
+			internalerrposition(syntaxerrposition);
+			internalerrquery(callback_arg->prosrc);
+		}
 	}
 
 	errcontext("SQL function \"%s\" during inlining", callback_arg->proname);
@@ -4853,7 +4877,6 @@ inline_set_returning_function(PlannerInfo *root, RangeTblEntry *rte)
 	Oid			func_oid;
 	HeapTuple	func_tuple;
 	Form_pg_proc funcform;
-	char	   *src;
 	Datum		tmp;
 	bool		isNull;
 	MemoryContext oldcxt;
@@ -4962,27 +4985,53 @@ inline_set_returning_function(PlannerInfo *root, RangeTblEntry *rte)
 								  ALLOCSET_DEFAULT_SIZES);
 	oldcxt = MemoryContextSwitchTo(mycxt);
 
-	/* Fetch the function body */
-	tmp = SysCacheGetAttr(PROCOID,
-						  func_tuple,
-						  Anum_pg_proc_prosrc,
-						  &isNull);
-	if (isNull)
-		elog(ERROR, "null prosrc for function %u", func_oid);
-	src = TextDatumGetCString(tmp);
-
 	/*
 	 * Setup error traceback support for ereport().  This is so that we can
 	 * finger the function that bad information came from.
 	 */
 	callback_arg.proname = NameStr(funcform->proname);
-	callback_arg.prosrc = src;
+	callback_arg.prosrc = NULL;
 
 	sqlerrcontext.callback = sql_inline_error_callback;
 	sqlerrcontext.arg = (void *) &callback_arg;
 	sqlerrcontext.previous = error_context_stack;
 	error_context_stack = &sqlerrcontext;
 
+	/* Fetch the function body */
+	tmp = SysCacheGetAttr(PROCOID,
+						  func_tuple,
+						  Anum_pg_proc_prosrc,
+						  &isNull);
+	if (isNull)
+	{
+		Node	   *n;
+
+		tmp = SysCacheGetAttr(PROCOID, func_tuple, Anum_pg_proc_prosqlbody, &isNull);
+		if (isNull)
+			elog(ERROR, "null prosrc and prosqlbody for function %u", func_oid);
+
+		n = stringToNode(TextDatumGetCString(tmp));
+		if (IsA(n, List))
+			querytree_list = linitial_node(List, castNode(List, n));
+		else
+			querytree_list = list_make1(n);
+		if (list_length(querytree_list) != 1)
+			goto fail;
+		querytree = linitial(querytree_list);
+
+		querytree_list = pg_rewrite_query(querytree);
+		if (list_length(querytree_list) != 1)
+			goto fail;
+		querytree = linitial(querytree_list);
+	}
+	else
+	{
+	char	   *src;
+
+	src = TextDatumGetCString(tmp);
+
+	callback_arg.prosrc = src;
+
 	/*
 	 * Set up to handle parameters while parsing the function body.  We can
 	 * use the FuncExpr just created as the input for
@@ -4992,18 +5041,6 @@ inline_set_returning_function(PlannerInfo *root, RangeTblEntry *rte)
 									  (Node *) fexpr,
 									  fexpr->inputcollid);
 
-	/*
-	 * Also resolve the actual function result tupdesc, if composite.  If the
-	 * function is just declared to return RECORD, dig the info out of the AS
-	 * clause.
-	 */
-	functypclass = get_expr_result_type((Node *) fexpr, NULL, &rettupdesc);
-	if (functypclass == TYPEFUNC_RECORD)
-		rettupdesc = BuildDescFromLists(rtfunc->funccolnames,
-										rtfunc->funccoltypes,
-										rtfunc->funccoltypmods,
-										rtfunc->funccolcollations);
-
 	/*
 	 * Parse, analyze, and rewrite (unlike inline_function(), we can't skip
 	 * rewriting here).  We can fail as soon as we find more than one query,
@@ -5020,6 +5057,19 @@ inline_set_returning_function(PlannerInfo *root, RangeTblEntry *rte)
 	if (list_length(querytree_list) != 1)
 		goto fail;
 	querytree = linitial(querytree_list);
+	}
+
+	/*
+	 * Also resolve the actual function result tupdesc, if composite.  If the
+	 * function is just declared to return RECORD, dig the info out of the AS
+	 * clause.
+	 */
+	functypclass = get_expr_result_type((Node *) fexpr, NULL, &rettupdesc);
+	if (functypclass == TYPEFUNC_RECORD)
+		rettupdesc = BuildDescFromLists(rtfunc->funccolnames,
+										rtfunc->funccoltypes,
+										rtfunc->funccoltypmods,
+										rtfunc->funccolcollations);
 
 	/*
 	 * The single command must be a plain SELECT.
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index c159fb2957..ed0622c5d7 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -66,6 +66,7 @@ static Node *transformSetOperationTree(ParseState *pstate, SelectStmt *stmt,
 									   bool isTopLevel, List **targetlist);
 static void determineRecursiveColTypes(ParseState *pstate,
 									   Node *larg, List *nrtargetlist);
+static Query *transformReturnStmt(ParseState *pstate, ReturnStmt *stmt);
 static Query *transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt);
 static List *transformReturningList(ParseState *pstate, List *returningList);
 static List *transformUpdateTargetList(ParseState *pstate,
@@ -304,6 +305,10 @@ transformStmt(ParseState *pstate, Node *parseTree)
 			}
 			break;
 
+		case T_ReturnStmt:
+			result = transformReturnStmt(pstate, (ReturnStmt *) parseTree);
+			break;
+
 			/*
 			 * Special cases
 			 */
@@ -2221,6 +2226,36 @@ determineRecursiveColTypes(ParseState *pstate, Node *larg, List *nrtargetlist)
 }

+/*
+ * transformReturnStmt -
+ *	  transforms a return statement
+ */
+static Query *
+transformReturnStmt(ParseState *pstate, ReturnStmt *stmt)
+{
+	Query	   *qry = makeNode(Query);
+
+	qry->commandType = CMD_SELECT;
+	qry->isReturn = true;
+
+	qry->targetList = list_make1(makeTargetEntry((Expr *) transformExpr(pstate, stmt->returnval, EXPR_KIND_SELECT_TARGET),
+												 1, NULL, false));
+
+	if (pstate->p_resolve_unknowns)
+		resolveTargetListUnknowns(pstate, qry->targetList);
+	qry->rtable = pstate->p_rtable;
+	qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
+	qry->hasSubLinks = pstate->p_hasSubLinks;
+	qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
+	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
+	qry->hasAggs = pstate->p_hasAggs;
+
+	assign_query_collations(pstate, qry);
+
+	return qry;
+}
+
+
 /*
  * transformUpdateStmt -
  *	  transforms an update statement
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 480d168346..e0f49a552f 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -253,7 +253,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	struct SelectLimit	*selectlimit;
 }
 
-%type <node>	stmt schema_stmt
+%type <node>	stmt toplevel_stmt schema_stmt routine_body_stmt
 		AlterEventTrigStmt AlterCollationStmt
 		AlterDatabaseStmt AlterDatabaseSetStmt AlterDomainStmt AlterEnumStmt
 		AlterFdwStmt AlterForeignServerStmt AlterGroupStmt
@@ -280,9 +280,9 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 		GrantStmt GrantRoleStmt ImportForeignSchemaStmt IndexStmt InsertStmt
 		ListenStmt LoadStmt LockStmt NotifyStmt ExplainableStmt PreparableStmt
 		CreateFunctionStmt AlterFunctionStmt ReindexStmt RemoveAggrStmt
-		RemoveFuncStmt RemoveOperStmt RenameStmt RevokeStmt RevokeRoleStmt
+		RemoveFuncStmt RemoveOperStmt RenameStmt ReturnStmt RevokeStmt RevokeRoleStmt
 		RuleActionStmt RuleActionStmtOrEmpty RuleStmt
-		SecLabelStmt SelectStmt TransactionStmt TruncateStmt
+		SecLabelStmt SelectStmt TransactionStmt TransactionStmtLegacy TruncateStmt
 		UnlistenStmt UpdateStmt VacuumStmt
 		VariableResetStmt VariableSetStmt VariableShowStmt
 		ViewStmt CheckPointStmt CreateConversionStmt
@@ -385,14 +385,14 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 %type <node>	vacuum_relation
 %type <selectlimit> opt_select_limit select_limit limit_clause
 
-%type <list>	stmtblock stmtmulti
+%type <list>	stmtblock stmtmulti routine_body_stmt_list
 				OptTableElementList TableElementList OptInherit definition
 				OptTypedTableElementList TypedTableElementList
 				reloptions opt_reloptions
 				OptWith distinct_clause opt_all_clause opt_definition func_args func_args_list
 				func_args_with_defaults func_args_with_defaults_list
 				aggr_args aggr_args_list
-				func_as createfunc_opt_list alterfunc_opt_list
+				func_as createfunc_opt_list opt_createfunc_opt_list alterfunc_opt_list
 				old_aggr_definition old_aggr_list
 				oper_argtypes RuleActionList RuleActionMulti
 				opt_column_list columnList opt_name_list
@@ -418,6 +418,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 				vacuum_relation_list opt_vacuum_relation_list
 				drop_option_list
 
+%type <node>	opt_routine_body
 %type <list>	group_by_list
 %type <node>	group_by_item empty_grouping_set rollup_clause cube_clause
 %type <node>	grouping_sets_clause
@@ -628,7 +629,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 /* ordinary key words in alphabetical order */
 %token <keyword> ABORT_P ABSOLUTE_P ACCESS ACTION ADD_P ADMIN AFTER
 	AGGREGATE ALL ALSO ALTER ALWAYS ANALYSE ANALYZE AND ANY ARRAY AS ASC
-	ASSERTION ASSIGNMENT ASYMMETRIC AT ATTACH ATTRIBUTE AUTHORIZATION
+	ASSERTION ASSIGNMENT ASYMMETRIC AT ATOMIC ATTACH ATTRIBUTE AUTHORIZATION
 
 	BACKWARD BEFORE BEGIN_P BETWEEN BIGINT BINARY BIT
 	BOOLEAN_P BOTH BY
@@ -690,7 +691,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 
 	RANGE READ REAL REASSIGN RECHECK RECURSIVE REF REFERENCES REFERENCING
 	REFRESH REINDEX RELATIVE_P RELEASE RENAME REPEATABLE REPLACE REPLICA
-	RESET RESTART RESTRICT RETURNING RETURNS REVOKE RIGHT ROLE ROLLBACK ROLLUP
+	RESET RESTART RESTRICT RETURN RETURNING RETURNS REVOKE RIGHT ROLE ROLLBACK ROLLUP
 	ROUTINE ROUTINES ROW ROWS RULE
 
 	SAVEPOINT SCHEMA SCHEMAS SCROLL SEARCH SECOND_P SECURITY SELECT SEQUENCE SEQUENCES
@@ -812,7 +813,7 @@ stmtblock:	stmtmulti
  * we'd get -1 for the location in such cases.
  * We also take care to discard empty statements entirely.
  */
-stmtmulti:	stmtmulti ';' stmt
+stmtmulti:	stmtmulti ';' toplevel_stmt
 				{
 					if ($1 != NIL)
 					{
@@ -824,7 +825,7 @@ stmtmulti:	stmtmulti ';' stmt
 					else
 						$$ = $1;
 				}
-			| stmt
+			| toplevel_stmt
 				{
 					if ($1 != NULL)
 						$$ = list_make1(makeRawStmt($1, 0));
@@ -833,7 +834,16 @@ stmtmulti:	stmtmulti ';' stmt
 				}
 		;
 
-stmt :
+/*
+ * toplevel_stmt includes BEGIN and END.  stmt does not include them, because
+ * those words have different meanings in function bodys.
+ */
+toplevel_stmt:
+			stmt
+			| TransactionStmtLegacy
+		;
+
+stmt:
 			AlterEventTrigStmt
 			| AlterCollationStmt
 			| AlterDatabaseStmt
@@ -7339,7 +7349,7 @@ opt_nulls_order: NULLS_LA FIRST_P			{ $$ = SORTBY_NULLS_FIRST; }
 
 CreateFunctionStmt:
 			CREATE opt_or_replace FUNCTION func_name func_args_with_defaults
-			RETURNS func_return createfunc_opt_list
+			RETURNS func_return opt_createfunc_opt_list opt_routine_body
 				{
 					CreateFunctionStmt *n = makeNode(CreateFunctionStmt);
 					n->is_procedure = false;
@@ -7348,10 +7358,11 @@ CreateFunctionStmt:
 					n->parameters = $5;
 					n->returnType = $7;
 					n->options = $8;
+					n->sql_body = $9;
 					$$ = (Node *)n;
 				}
 			| CREATE opt_or_replace FUNCTION func_name func_args_with_defaults
-			  RETURNS TABLE '(' table_func_column_list ')' createfunc_opt_list
+			  RETURNS TABLE '(' table_func_column_list ')' opt_createfunc_opt_list opt_routine_body
 				{
 					CreateFunctionStmt *n = makeNode(CreateFunctionStmt);
 					n->is_procedure = false;
@@ -7361,10 +7372,11 @@ CreateFunctionStmt:
 					n->returnType = TableFuncTypeName($9);
 					n->returnType->location = @7;
 					n->options = $11;
+					n->sql_body = $12;
 					$$ = (Node *)n;
 				}
 			| CREATE opt_or_replace FUNCTION func_name func_args_with_defaults
-			  createfunc_opt_list
+			  opt_createfunc_opt_list opt_routine_body
 				{
 					CreateFunctionStmt *n = makeNode(CreateFunctionStmt);
 					n->is_procedure = false;
@@ -7373,10 +7385,11 @@ CreateFunctionStmt:
 					n->parameters = $5;
 					n->returnType = NULL;
 					n->options = $6;
+					n->sql_body = $7;
 					$$ = (Node *)n;
 				}
 			| CREATE opt_or_replace PROCEDURE func_name func_args_with_defaults
-			  createfunc_opt_list
+			  opt_createfunc_opt_list opt_routine_body
 				{
 					CreateFunctionStmt *n = makeNode(CreateFunctionStmt);
 					n->is_procedure = true;
@@ -7385,6 +7398,7 @@ CreateFunctionStmt:
 					n->parameters = $5;
 					n->returnType = NULL;
 					n->options = $6;
+					n->sql_body = $7;
 					$$ = (Node *)n;
 				}
 		;
@@ -7695,6 +7709,11 @@ aggregate_with_argtypes_list:
 													{ $$ = lappend($1, $3); }
 		;
 
+opt_createfunc_opt_list:
+			createfunc_opt_list
+			| /*EMPTY*/ { $$ = NIL; }
+	;
+
 createfunc_opt_list:
 			/* Must be at least one to prevent conflict */
 			createfunc_opt_item						{ $$ = list_make1($1); }
@@ -7806,6 +7825,51 @@ func_as:	Sconst						{ $$ = list_make1(makeString($1)); }
 				}
 		;
 
+ReturnStmt:	RETURN a_expr
+				{
+					ReturnStmt *r = makeNode(ReturnStmt);
+					r->returnval = (Node *) $2;
+					$$ = (Node *) r;
+				}
+		;
+
+opt_routine_body:
+			ReturnStmt
+				{
+					$$ = $1;
+				}
+			| BEGIN_P ATOMIC routine_body_stmt_list END_P
+				{
+					/*
+					 * A compound statement is stored as a single-item list
+					 * containing the list of statements as its member.  That
+					 * way, the parse analysis code can tell apart an empty
+					 * body from no body at all.
+					 */
+					$$ = (Node *) list_make1($3);
+				}
+			| /*EMPTY*/
+				{
+					$$ = NULL;
+				}
+		;
+
+routine_body_stmt_list:
+			routine_body_stmt_list routine_body_stmt ';'
+				{
+					$$ = lappend($1, $2);
+				}
+			| /*EMPTY*/
+				{
+					$$ = NIL;
+				}
+		;
+
+routine_body_stmt:
+			stmt
+			| ReturnStmt
+		;
+
 transform_type_list:
 			FOR TYPE_P Typename { $$ = list_make1($3); }
 			| transform_type_list ',' FOR TYPE_P Typename { $$ = lappend($1, $5); }
@@ -9756,13 +9820,6 @@ TransactionStmt:
 					n->chain = $3;
 					$$ = (Node *)n;
 				}
-			| BEGIN_P opt_transaction transaction_mode_list_or_empty
-				{
-					TransactionStmt *n = makeNode(TransactionStmt);
-					n->kind = TRANS_STMT_BEGIN;
-					n->options = $3;
-					$$ = (Node *)n;
-				}
 			| START TRANSACTION transaction_mode_list_or_empty
 				{
 					TransactionStmt *n = makeNode(TransactionStmt);
@@ -9778,14 +9835,6 @@ TransactionStmt:
 					n->chain = $3;
 					$$ = (Node *)n;
 				}
-			| END_P opt_transaction opt_transaction_chain
-				{
-					TransactionStmt *n = makeNode(TransactionStmt);
-					n->kind = TRANS_STMT_COMMIT;
-					n->options = NIL;
-					n->chain = $3;
-					$$ = (Node *)n;
-				}
 			| ROLLBACK opt_transaction opt_transaction_chain
 				{
 					TransactionStmt *n = makeNode(TransactionStmt);
@@ -9852,6 +9901,24 @@ TransactionStmt:
 				}
 		;
 
+TransactionStmtLegacy:
+			BEGIN_P opt_transaction transaction_mode_list_or_empty
+				{
+					TransactionStmt *n = makeNode(TransactionStmt);
+					n->kind = TRANS_STMT_BEGIN;
+					n->options = $3;
+					$$ = (Node *)n;
+				}
+			| END_P opt_transaction opt_transaction_chain
+				{
+					TransactionStmt *n = makeNode(TransactionStmt);
+					n->kind = TRANS_STMT_COMMIT;
+					n->options = NIL;
+					n->chain = $3;
+					$$ = (Node *)n;
+				}
+		;
+
 opt_transaction:	WORK							{}
 			| TRANSACTION							{}
 			| /*EMPTY*/								{}
@@ -15074,6 +15141,7 @@ unreserved_keyword:
 			| ASSERTION
 			| ASSIGNMENT
 			| AT
+			| ATOMIC
 			| ATTACH
 			| ATTRIBUTE
 			| BACKWARD
@@ -15272,6 +15340,7 @@ unreserved_keyword:
 			| RESET
 			| RESTART
 			| RESTRICT
+			| RETURN
 			| RETURNS
 			| REVOKE
 			| ROLE
@@ -15578,6 +15647,7 @@ bare_label_keyword:
 			| ASSIGNMENT
 			| ASYMMETRIC
 			| AT
+			| ATOMIC
 			| ATTACH
 			| ATTRIBUTE
 			| AUTHORIZATION
@@ -15848,6 +15918,7 @@ bare_label_keyword:
 			| RESET
 			| RESTART
 			| RESTRICT
+			| RETURN
 			| RETURNS
 			| REVOKE
 			| RIGHT
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 411cfadbff..e145f552c0 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -176,7 +176,6 @@ static int	interactive_getc(void);
 static int	SocketBackend(StringInfo inBuf);
 static int	ReadCommand(StringInfo inBuf);
 static void forbidden_in_wal_sender(char firstchar);
-static List *pg_rewrite_query(Query *query);
 static bool check_log_statement(List *stmt_list);
 static int	errdetail_execute(List *raw_parsetree_list);
 static int	errdetail_params(ParamListInfo params);
@@ -761,7 +760,7 @@ pg_analyze_and_rewrite_params(RawStmt *parsetree,
  * Note: query must just have come from the parser, because we do not do
  * AcquireRewriteLocks() on it.
  */
-static List *
+List *
 pg_rewrite_query(Query *query)
 {
 	List	   *querytree_list;
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 6c656586e8..6a52686cca 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -174,6 +174,9 @@ typedef struct
 	List	   *outer_tlist;	/* referent for OUTER_VAR Vars */
 	List	   *inner_tlist;	/* referent for INNER_VAR Vars */
 	List	   *index_tlist;	/* referent for INDEX_VAR Vars */
+	/* Special namespace representing a function signature: */
+	int			numargs;
+	char	  **argnames;
 } deparse_namespace;
 
 /*
@@ -349,6 +352,7 @@ static int	print_function_arguments(StringInfo buf, HeapTuple proctup,
 									 bool print_table_args, bool print_defaults);
 static void print_function_rettype(StringInfo buf, HeapTuple proctup);
 static void print_function_trftypes(StringInfo buf, HeapTuple proctup);
+static void print_function_sqlbody(StringInfo buf, HeapTuple proctup);
 static void set_rtable_names(deparse_namespace *dpns, List *parent_namespaces,
 							 Bitmapset *rels_used);
 static void set_deparse_for_query(deparse_namespace *dpns, Query *query,
@@ -2800,6 +2804,13 @@ pg_get_functiondef(PG_FUNCTION_ARGS)
 	}
 
 	/* And finally the function definition ... */
+	tmp = SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_prosqlbody, &isnull);
+	if (proc->prolang == SQLlanguageId && !isnull)
+	{
+		print_function_sqlbody(&buf, proctup);
+	}
+	else
+	{
 	appendStringInfoString(&buf, "AS ");
 
 	tmp = SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_probin, &isnull);
@@ -2831,6 +2842,7 @@ pg_get_functiondef(PG_FUNCTION_ARGS)
 	appendBinaryStringInfo(&buf, dq.data, dq.len);
 	appendStringInfoString(&buf, prosrc);
 	appendBinaryStringInfo(&buf, dq.data, dq.len);
+	}
 
 	appendStringInfoChar(&buf, '\n');
 
@@ -3213,6 +3225,75 @@ pg_get_function_arg_default(PG_FUNCTION_ARGS)
 	PG_RETURN_TEXT_P(string_to_text(str));
 }
 
+static void
+print_function_sqlbody(StringInfo buf, HeapTuple proctup)
+{
+	int			numargs;
+	Oid		   *argtypes;
+	char	  **argnames;
+	char	   *argmodes;
+	deparse_namespace dpns = {0};
+	Datum		tmp;
+	bool		isnull;
+	Node	   *n;
+
+	numargs = get_func_arg_info(proctup,
+								&argtypes, &argnames, &argmodes);
+	dpns.numargs = numargs;
+	dpns.argnames = argnames;
+
+	tmp = SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_prosqlbody, &isnull);
+	Assert(!isnull);
+	n = stringToNode(TextDatumGetCString(tmp));
+
+	if (IsA(n, List))
+	{
+		List       *stmts;
+		ListCell   *lc;
+
+		stmts = linitial(castNode(List, n));
+
+		appendStringInfoString(buf, "BEGIN ATOMIC\n");
+
+		foreach(lc, stmts)
+		{
+			Query	   *query = lfirst_node(Query, lc);
+
+			get_query_def(query, buf, list_make1(&dpns), NULL, PRETTYFLAG_INDENT, WRAP_COLUMN_DEFAULT, 1);
+			appendStringInfoChar(buf, ';');
+			appendStringInfoChar(buf, '\n');
+		}
+
+		appendStringInfoString(buf, "END");
+	}
+	else
+	{
+		get_query_def(castNode(Query, n), buf, list_make1(&dpns), NULL, PRETTYFLAG_INDENT, WRAP_COLUMN_DEFAULT, 1);
+		appendStringInfoChar(buf, '\n');
+	}
+}
+
+Datum
+pg_get_function_sqlbody(PG_FUNCTION_ARGS)
+{
+	Oid			funcid = PG_GETARG_OID(0);
+	StringInfoData buf;
+	HeapTuple	proctup;
+
+	initStringInfo(&buf);
+
+	/* Look up the function */
+	proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
+	if (!HeapTupleIsValid(proctup))
+		PG_RETURN_NULL();
+
+	print_function_sqlbody(&buf, proctup);
+
+	ReleaseSysCache(proctup);
+
+	PG_RETURN_TEXT_P(cstring_to_text(buf.data));
+}
+
 
 /*
  * deparse_expression			- General utility for deparsing expressions
@@ -5418,7 +5499,10 @@ get_basic_select_query(Query *query, deparse_context *context,
 	/*
 	 * Build up the query string - first we say SELECT
 	 */
-	appendStringInfoString(buf, "SELECT");
+	if (query->isReturn)
+		appendStringInfoString(buf, "RETURN");
+	else
+		appendStringInfoString(buf, "SELECT");
 
 	/* Add the DISTINCT clause if given */
 	if (query->distinctClause != NIL)
@@ -7550,6 +7634,26 @@ get_parameter(Param *param, deparse_context *context)
 		return;
 	}
 
+	/*
+	 * If it's an external parameter, see if the outermost namespace provides
+	 * function argument names.
+	 */
+	if (param->paramkind == PARAM_EXTERN)
+	{
+		dpns = lfirst(list_tail(context->namespaces));
+		if (dpns->argnames)
+		{
+			char	   *argname = dpns->argnames[param->paramid - 1];
+
+			if (argname)
+			{
+				// TODO: qualify with function name if necessary
+				appendStringInfo(context->buf, "%s", quote_identifier(argname));
+				return;
+			}
+		}
+	}
+
 	/*
 	 * Not PARAM_EXEC, or couldn't find referent: just print $N.
 	 */
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index ff45e3fb8c..8acbab80c8 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -11803,6 +11803,7 @@ dumpFunc(Archive *fout, FuncInfo *finfo)
 	char	   *proretset;
 	char	   *prosrc;
 	char	   *probin;
+	char	   *prosqlbody;
 	char	   *funcargs;
 	char	   *funciargs;
 	char	   *funcresult;
@@ -11849,7 +11850,7 @@ dumpFunc(Archive *fout, FuncInfo *finfo)
 						 "provolatile,\n"
 						 "proisstrict,\n"
 						 "prosecdef,\n"
-						 "(SELECT lanname FROM pg_catalog.pg_language WHERE oid = prolang) AS lanname,\n");
+						 "lanname,\n");
 
 	if (fout->remoteVersion >= 80300)
 		appendPQExpBufferStr(query,
@@ -11869,9 +11870,9 @@ dumpFunc(Archive *fout, FuncInfo *finfo)
 		 * pg_get_function_result instead of examining proallargtypes etc.
 		 */
 		appendPQExpBufferStr(query,
-							 "pg_catalog.pg_get_function_arguments(oid) AS funcargs,\n"
-							 "pg_catalog.pg_get_function_identity_arguments(oid) AS funciargs,\n"
-							 "pg_catalog.pg_get_function_result(oid) AS funcresult,\n");
+							 "pg_catalog.pg_get_function_arguments(p.oid) AS funcargs,\n"
+							 "pg_catalog.pg_get_function_identity_arguments(p.oid) AS funciargs,\n"
+							 "pg_catalog.pg_get_function_result(p.oid) AS funcresult,\n");
 	}
 	else if (fout->remoteVersion >= 80100)
 		appendPQExpBufferStr(query,
@@ -11914,21 +11915,39 @@ dumpFunc(Archive *fout, FuncInfo *finfo)
 
 	if (fout->remoteVersion >= 120000)
 		appendPQExpBufferStr(query,
-							 "prosupport\n");
+							 "prosupport,\n");
 	else
 		appendPQExpBufferStr(query,
-							 "'-' AS prosupport\n");
+							 "'-' AS prosupport,\n");
+
+	if (fout->remoteVersion >= 140000)
+		appendPQExpBufferStr(query,
+							 "CASE WHEN prosrc IS NULL AND lanname = 'sql' THEN pg_get_function_sqlbody(p.oid) END AS prosqlbody\n");
+	else
+		appendPQExpBufferStr(query,
+							 "NULL AS prosqlbody\n");
 
 	appendPQExpBuffer(query,
-					  "FROM pg_catalog.pg_proc "
-					  "WHERE oid = '%u'::pg_catalog.oid",
+					  "FROM pg_catalog.pg_proc p, pg_catalog.pg_language l\n"
+					  "WHERE p.oid = '%u'::pg_catalog.oid "
+					  "AND l.oid = p.prolang",
 					  finfo->dobj.catId.oid);
 
 	res = ExecuteSqlQueryForSingleRow(fout, query->data);
 
 	proretset = PQgetvalue(res, 0, PQfnumber(res, "proretset"));
-	prosrc = PQgetvalue(res, 0, PQfnumber(res, "prosrc"));
-	probin = PQgetvalue(res, 0, PQfnumber(res, "probin"));
+	if (PQgetisnull(res, 0, PQfnumber(res, "prosqlbody")))
+	{
+		prosrc = PQgetvalue(res, 0, PQfnumber(res, "prosrc"));
+		probin = PQgetvalue(res, 0, PQfnumber(res, "probin"));
+		prosqlbody = NULL;
+	}
+	else
+	{
+		prosrc = NULL;
+		probin = NULL;
+		prosqlbody = PQgetvalue(res, 0, PQfnumber(res, "prosqlbody"));
+	}
 	if (fout->remoteVersion >= 80400)
 	{
 		funcargs = PQgetvalue(res, 0, PQfnumber(res, "funcargs"));
@@ -11965,7 +11984,11 @@ dumpFunc(Archive *fout, FuncInfo *finfo)
 	 * versions would set it to "-".  There are no known cases in which prosrc
 	 * is unused, so the tests below for "-" are probably useless.
 	 */
-	if (probin[0] != '\0' && strcmp(probin, "-") != 0)
+	if (prosqlbody)
+	{
+		appendPQExpBufferStr(asPart, prosqlbody);
+	}
+	else if (probin[0] != '\0' && strcmp(probin, "-") != 0)
 	{
 		appendPQExpBufferStr(asPart, "AS ");
 		appendStringLiteralAH(asPart, probin, fout);
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 07d640021c..319c34ff2b 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -505,11 +505,18 @@ describeFunctions(const char *functypes, const char *pattern, bool verbose, bool
 		appendPQExpBufferStr(&buf, ",\n ");
 		printACLColumn(&buf, "p.proacl");
 		appendPQExpBuffer(&buf,
-						  ",\n l.lanname as \"%s\""
-						  ",\n p.prosrc as \"%s\""
+						  ",\n l.lanname as \"%s\"",
+						  gettext_noop("Language"));
+		if (pset.sversion >= 140000)
+			appendPQExpBuffer(&buf,
+							  ",\n COALESCE(p.prosrc, pg_catalog.pg_get_function_sqlbody(p.oid)) as \"%s\"",
+							  gettext_noop("Source code"));
+		else
+			appendPQExpBuffer(&buf,
+							  ",\n p.prosrc as \"%s\"",
+							  gettext_noop("Source code"));
+		appendPQExpBuffer(&buf,
 						  ",\n pg_catalog.obj_description(p.oid, 'pg_proc') as \"%s\"",
-						  gettext_noop("Language"),
-						  gettext_noop("Source code"),
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/fe_utils/psqlscan.l b/src/fe_utils/psqlscan.l
index 08dffde1ba..ee34463e67 100644
--- a/src/fe_utils/psqlscan.l
+++ b/src/fe_utils/psqlscan.l
@@ -645,10 +645,11 @@ other			.
 
 ";"				{
 					ECHO;
-					if (cur_state->paren_depth == 0)
+					if (cur_state->paren_depth == 0 && cur_state->begin_depth == 0)
 					{
 						/* Terminate lexing temporarily */
 						cur_state->start_state = YY_START;
+						cur_state->identifier_count = 0;
 						return LEXRES_SEMI;
 					}
 				}
@@ -661,6 +662,8 @@ other			.
 "\\"[;:]		{
 					/* Force a semi-colon or colon into the query buffer */
 					psqlscan_emit(cur_state, yytext + 1, 1);
+					if (yytext[1] == ';')
+						cur_state->identifier_count = 0;
 				}
 
 "\\"			{
@@ -867,6 +870,17 @@ other			.

 {identifier}	{
+					cur_state->identifier_count++;
+					if (pg_strcasecmp(yytext, "begin") == 0)
+					{
+						if (cur_state->identifier_count > 1)
+							cur_state->begin_depth++;
+					}
+					else if (pg_strcasecmp(yytext, "end") == 0)
+					{
+						if (cur_state->begin_depth > 0)
+							cur_state->begin_depth--;
+					}
 					ECHO;
 				}
 
@@ -1054,6 +1068,11 @@ psql_scan(PsqlScanState state,
 						result = PSCAN_INCOMPLETE;
 						*prompt = PROMPT_PAREN;
 					}
+					if (state->begin_depth > 0)
+					{
+						result = PSCAN_INCOMPLETE;
+						*prompt = PROMPT_CONTINUE;
+					}
 					else if (query_buf->len > 0)
 					{
 						result = PSCAN_EOL;
@@ -1170,6 +1189,8 @@ psql_scan_reset(PsqlScanState state)
 	if (state->dolqstart)
 		free(state->dolqstart);
 	state->dolqstart = NULL;
+	state->identifier_count = 0;
+	state->begin_depth = 0;
 }
 
 /*
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index bbcac69d48..71bf2d8cc6 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -3681,6 +3681,10 @@
   proname => 'pg_get_function_arg_default', provolatile => 's',
   prorettype => 'text', proargtypes => 'oid int4',
   prosrc => 'pg_get_function_arg_default' },
+{ oid => '9704', descr => 'function SQL body',
+  proname => 'pg_get_function_sqlbody', provolatile => 's',
+  prorettype => 'text', proargtypes => 'oid',
+  prosrc => 'pg_get_function_sqlbody' },
 
 { oid => '1686', descr => 'list of SQL keywords',
   proname => 'pg_get_keywords', procost => '10', prorows => '500',
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 268c810896..720d6c77ad 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -112,11 +112,14 @@ CATALOG(pg_proc,1255,ProcedureRelationId) BKI_BOOTSTRAP BKI_ROWTYPE_OID(81,Proce
 	Oid			protrftypes[1] BKI_DEFAULT(_null_);
 
 	/* procedure source text */
-	text		prosrc BKI_FORCE_NOT_NULL;
+	text		prosrc;
 
 	/* secondary procedure info (can be NULL) */
 	text		probin BKI_DEFAULT(_null_);
 
+	/* pre-parsed SQL function body */
+	pg_node_tree prosqlbody BKI_DEFAULT(_null_);
+
 	/* procedure-local GUC settings */
 	text		proconfig[1] BKI_DEFAULT(_null_);
 
@@ -187,6 +190,7 @@ extern ObjectAddress ProcedureCreate(const char *procedureName,
 									 Oid languageValidator,
 									 const char *prosrc,
 									 const char *probin,
+									 Node *prosqlbody,
 									 char prokind,
 									 bool security_definer,
 									 bool isLeakProof,
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 7a079ef07f..a32cfba421 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -68,9 +68,11 @@ extern void interpret_function_parameter_list(ParseState *pstate,
 											  Oid languageOid,
 											  ObjectType objtype,
 											  oidvector **parameterTypes,
+											  List **parameterTypes_list,
 											  ArrayType **allParameterTypes,
 											  ArrayType **parameterModes,
 											  ArrayType **parameterNames,
+											  List **inParameterNames_list,
 											  List **parameterDefaults,
 											  Oid *variadicArgType,
 											  Oid *requiredResultType);
diff --git a/src/include/executor/functions.h b/src/include/executor/functions.h
index a0db24bde6..3111ff824a 100644
--- a/src/include/executor/functions.h
+++ b/src/include/executor/functions.h
@@ -20,6 +20,21 @@
 /* This struct is known only within executor/functions.c */
 typedef struct SQLFunctionParseInfo *SQLFunctionParseInfoPtr;
 
+/*
+ * Data structure needed by the parser callback hooks to resolve parameter
+ * references during parsing of a SQL function's body.  This is separate from
+ * SQLFunctionCache since we sometimes do parsing separately from execution.
+ */
+typedef struct SQLFunctionParseInfo
+{
+	char	   *fname;			/* function's name */
+	int			nargs;			/* number of input arguments */
+	Oid		   *argtypes;		/* resolved types of input arguments */
+	char	  **argnames;		/* names of input arguments; NULL if none */
+	/* Note that argnames[i] can be NULL, if some args are unnamed */
+	Oid			collation;		/* function's input collation, if known */
+}			SQLFunctionParseInfo;
+
 extern Datum fmgr_sql(PG_FUNCTION_ARGS);
 
 extern SQLFunctionParseInfoPtr prepare_sql_fn_parse_info(HeapTuple procedureTuple,
diff --git a/src/include/fe_utils/psqlscan_int.h b/src/include/fe_utils/psqlscan_int.h
index 311f80394a..fb8f58aa29 100644
--- a/src/include/fe_utils/psqlscan_int.h
+++ b/src/include/fe_utils/psqlscan_int.h
@@ -114,6 +114,8 @@ typedef struct PsqlScanStateData
 	int			paren_depth;	/* depth of nesting in parentheses */
 	int			xcdepth;		/* depth of nesting in slash-star comments */
 	char	   *dolqstart;		/* current $foo$ quote start string */
+	int			identifier_count;	/* identifiers since start of statement */
+	int			begin_depth;	/* depth of begin/end routine body blocks */
 
 	/*
 	 * Callback functions provided by the program making use of the lexer,
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 7ddd8c011b..f5716a3eb0 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -315,6 +315,7 @@ typedef enum NodeTag
 	T_DeleteStmt,
 	T_UpdateStmt,
 	T_SelectStmt,
+	T_ReturnStmt,
 	T_AlterTableStmt,
 	T_AlterTableCmd,
 	T_AlterDomainStmt,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 60c2f45466..f0c0c307f9 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -132,6 +132,8 @@ typedef struct Query
 	bool		hasForUpdate;	/* FOR [KEY] UPDATE/SHARE was specified */
 	bool		hasRowSecurity; /* rewriter has applied some RLS policy */
 
+	bool		isReturn;		/* is a RETURN statement */
+
 	List	   *cteList;		/* WITH list (of CommonTableExpr's) */
 
 	List	   *rtable;			/* list of range table entries */
@@ -1671,6 +1673,16 @@ typedef struct SetOperationStmt
 } SetOperationStmt;

+/*
+ * RETURN statement (inside SQL function body)
+ */
+typedef struct ReturnStmt
+{
+	NodeTag		type;
+	Node	   *returnval;
+} ReturnStmt;
+
+
 /*****************************************************************************
  *		Other Statements (no optimizations required)
  *
@@ -2842,6 +2854,7 @@ typedef struct CreateFunctionStmt
 	List	   *parameters;		/* a list of FunctionParameter */
 	TypeName   *returnType;		/* the return type */
 	List	   *options;		/* a list of DefElem */
+	Node	   *sql_body;
 } CreateFunctionStmt;
 
 typedef enum FunctionParameterMode
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 71dcdf2889..36317a14db 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -48,6 +48,7 @@ PG_KEYWORD("assertion", ASSERTION, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("assignment", ASSIGNMENT, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("asymmetric", ASYMMETRIC, RESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("at", AT, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("atomic", ATOMIC, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("attach", ATTACH, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("attribute", ATTRIBUTE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("authorization", AUTHORIZATION, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
@@ -344,6 +345,7 @@ PG_KEYWORD("replica", REPLICA, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("reset", RESET, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("restart", RESTART, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("restrict", RESTRICT, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("return", RETURN, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("returning", RETURNING, RESERVED_KEYWORD, AS_LABEL)
 PG_KEYWORD("returns", RETURNS, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("revoke", REVOKE, UNRESERVED_KEYWORD, BARE_LABEL)
diff --git a/src/include/tcop/tcopprot.h b/src/include/tcop/tcopprot.h
index bd30607b07..e626c8eafd 100644
--- a/src/include/tcop/tcopprot.h
+++ b/src/include/tcop/tcopprot.h
@@ -43,6 +43,7 @@ typedef enum
 extern PGDLLIMPORT int log_statement;
 
 extern List *pg_parse_query(const char *query_string);
+extern List *pg_rewrite_query(Query *query);
 extern List *pg_analyze_and_rewrite(RawStmt *parsetree,
 									const char *query_string,
 									Oid *paramTypes, int numParams,
diff --git a/src/interfaces/ecpg/preproc/ecpg.addons b/src/interfaces/ecpg/preproc/ecpg.addons
index 300381eaad..0441561c52 100644
--- a/src/interfaces/ecpg/preproc/ecpg.addons
+++ b/src/interfaces/ecpg/preproc/ecpg.addons
@@ -87,6 +87,12 @@ ECPG: stmtTransactionStmt block
 		whenever_action(2);
 		free($1);
 	}
+ECPG: toplevel_stmtTransactionStmtLegacy block
+	{
+		fprintf(base_yyout, "{ ECPGtrans(__LINE__, %s, \"%s\");", connection ? connection : "NULL", $1);
+		whenever_action(2);
+		free($1);
+	}
 ECPG: stmtViewStmt rule
 	| ECPGAllocateDescr
 	{
diff --git a/src/interfaces/ecpg/preproc/ecpg.trailer b/src/interfaces/ecpg/preproc/ecpg.trailer
index 6ccc8ab916..7f4be655f9 100644
--- a/src/interfaces/ecpg/preproc/ecpg.trailer
+++ b/src/interfaces/ecpg/preproc/ecpg.trailer
@@ -4,8 +4,8 @@ statements: /*EMPTY*/
 				| statements statement
 		;
 
-statement: ecpgstart at stmt ';' { connection = NULL; }
-				| ecpgstart stmt ';'
+statement: ecpgstart at toplevel_stmt ';' { connection = NULL; }
+				| ecpgstart toplevel_stmt ';'
 				| ecpgstart ECPGVarDeclaration
 				{
 					fprintf(base_yyout, "%s", $2);
diff --git a/src/test/regress/expected/create_function_3.out b/src/test/regress/expected/create_function_3.out
index ce508ae1dc..dbd6358ffd 100644
--- a/src/test/regress/expected/create_function_3.out
+++ b/src/test/regress/expected/create_function_3.out
@@ -255,6 +255,151 @@ SELECT pg_get_functiondef('functest_F_2'::regproc);
  
 (1 row)
 
+--
+-- SQL-standard body
+--
+CREATE FUNCTION functest_S_1(a text, b date) RETURNS boolean
+    LANGUAGE SQL
+    RETURN a = 'abcd' AND b > '2001-01-01';
+CREATE FUNCTION functest_S_2(a text[]) RETURNS int
+    RETURN a[1]::int;
+CREATE FUNCTION functest_S_3() RETURNS boolean
+    RETURN false;
+CREATE FUNCTION functest_S_3a() RETURNS boolean
+    BEGIN ATOMIC
+        RETURN false;
+    END;
+CREATE FUNCTION functest_S_10(a text, b date) RETURNS boolean
+    LANGUAGE SQL
+    BEGIN ATOMIC
+        SELECT a = 'abcd' AND b > '2001-01-01';
+    END;
+CREATE FUNCTION functest_S_13() RETURNS boolean
+    BEGIN ATOMIC
+        SELECT 1;
+        SELECT false;
+    END;
+-- polymorphic arguments not allowed in this form
+CREATE FUNCTION functest_S_xx(x anyarray) RETURNS anyelement
+    LANGUAGE SQL
+    RETURN x[1];
+ERROR:  SQL function with unquoted function body cannot have polymorphic arguments
+SELECT functest_S_1('abcd', '2020-01-01');
+ functest_s_1 
+--------------
+ t
+(1 row)
+
+SELECT functest_S_2(ARRAY['1', '2', '3']);
+ functest_s_2 
+--------------
+            1
+(1 row)
+
+SELECT functest_S_3();
+ functest_s_3 
+--------------
+ f
+(1 row)
+
+SELECT functest_S_10('abcd', '2020-01-01');
+ functest_s_10 
+---------------
+ t
+(1 row)
+
+SELECT functest_S_13();
+ functest_s_13 
+---------------
+ f
+(1 row)
+
+SELECT pg_get_functiondef('functest_S_1'::regproc);
+                           pg_get_functiondef                           
+------------------------------------------------------------------------
+ CREATE OR REPLACE FUNCTION temp_func_test.functest_s_1(a text, b date)+
+  RETURNS boolean                                                      +
+  LANGUAGE sql                                                         +
+  RETURN ((a = 'abcd'::text) AND (b > '01-01-2001'::date))             +
+                                                                       +
+ 
+(1 row)
+
+SELECT pg_get_functiondef('functest_S_2'::regproc);
+                        pg_get_functiondef                        
+------------------------------------------------------------------
+ CREATE OR REPLACE FUNCTION temp_func_test.functest_s_2(a text[])+
+  RETURNS integer                                                +
+  LANGUAGE sql                                                   +
+  RETURN ((a)[1])::integer                                       +
+                                                                 +
+ 
+(1 row)
+
+SELECT pg_get_functiondef('functest_S_3'::regproc);
+                    pg_get_functiondef                    
+----------------------------------------------------------
+ CREATE OR REPLACE FUNCTION temp_func_test.functest_s_3()+
+  RETURNS boolean                                        +
+  LANGUAGE sql                                           +
+  RETURN false                                           +
+                                                         +
+ 
+(1 row)
+
+SELECT pg_get_functiondef('functest_S_3a'::regproc);
+                    pg_get_functiondef                     
+-----------------------------------------------------------
+ CREATE OR REPLACE FUNCTION temp_func_test.functest_s_3a()+
+  RETURNS boolean                                         +
+  LANGUAGE sql                                            +
+ BEGIN ATOMIC                                             +
+  RETURN false;                                           +
+ END                                                      +
+ 
+(1 row)
+
+SELECT pg_get_functiondef('functest_S_10'::regproc);
+                           pg_get_functiondef                            
+-------------------------------------------------------------------------
+ CREATE OR REPLACE FUNCTION temp_func_test.functest_s_10(a text, b date)+
+  RETURNS boolean                                                       +
+  LANGUAGE sql                                                          +
+ BEGIN ATOMIC                                                           +
+  SELECT ((a = 'abcd'::text) AND (b > '01-01-2001'::date));             +
+ END                                                                    +
+ 
+(1 row)
+
+SELECT pg_get_functiondef('functest_S_13'::regproc);
+                    pg_get_functiondef                     
+-----------------------------------------------------------
+ CREATE OR REPLACE FUNCTION temp_func_test.functest_s_13()+
+  RETURNS boolean                                         +
+  LANGUAGE sql                                            +
+ BEGIN ATOMIC                                             +
+  SELECT 1;                                               +
+  SELECT false AS bool;                                   +
+ END                                                      +
+ 
+(1 row)
+
+-- test with views
+CREATE TABLE functest3 (a int);
+INSERT INTO functest3 VALUES (1), (2);
+CREATE VIEW functestv3 AS SELECT * FROM functest3;
+CREATE FUNCTION functest_S_14() RETURNS bigint
+    RETURN (SELECT count(*) FROM functestv3);
+SELECT functest_S_14();
+ functest_s_14 
+---------------
+             2
+(1 row)
+
+DROP TABLE functest3 CASCADE;
+NOTICE:  drop cascades to 2 other objects
+DETAIL:  drop cascades to view functestv3
+drop cascades to function functest_s_14()
 -- information_schema tests
 CREATE FUNCTION functest_IS_1(a int, b int default 1, c text default 'foo')
     RETURNS int
@@ -284,6 +429,20 @@ SELECT routine_name, ordinal_position, parameter_name, parameter_default
 (7 rows)
 
 DROP FUNCTION functest_IS_1(int, int, text), functest_IS_2(int), functest_IS_3(int);
+CREATE TABLE functest1 (a int, b int);
+CREATE SEQUENCE functest2;
+CREATE FUNCTION functest_IS_4()
+    RETURNS int
+    LANGUAGE SQL
+    RETURN (SELECT count(a) FROM functest1);
+CREATE FUNCTION functest_IS_5()
+    RETURNS int
+    LANGUAGE SQL
+    RETURN nextval('functest2');
+DROP TABLE functest1 CASCADE;
+NOTICE:  drop cascades to function functest_is_4()
+DROP SEQUENCE functest2 CASCADE;
+NOTICE:  drop cascades to function functest_is_5()
 -- overload
 CREATE FUNCTION functest_B_2(bigint) RETURNS bool LANGUAGE 'sql'
        IMMUTABLE AS 'SELECT $1 > 0';
@@ -302,6 +461,49 @@ CREATE OR REPLACE PROCEDURE functest1(a int) LANGUAGE SQL AS 'SELECT $1';
 ERROR:  cannot change routine kind
 DETAIL:  "functest1" is a function.
 DROP FUNCTION functest1(a int);
+-- inlining of set-returning functions
+CREATE FUNCTION functest_sri1() RETURNS SETOF int
+LANGUAGE SQL
+STABLE
+AS '
+    VALUES (1), (2), (3);
+';
+SELECT * FROM functest_sri1();
+ functest_sri1 
+---------------
+             1
+             2
+             3
+(3 rows)
+
+EXPLAIN (verbose, costs off) SELECT * FROM functest_sri1();
+          QUERY PLAN          
+------------------------------
+ Values Scan on "*VALUES*"
+   Output: "*VALUES*".column1
+(2 rows)
+
+CREATE FUNCTION functest_sri2() RETURNS SETOF int
+LANGUAGE SQL
+STABLE
+BEGIN ATOMIC
+    VALUES (1), (2), (3);
+END;
+SELECT * FROM functest_sri2();
+ functest_sri2 
+---------------
+             1
+             2
+             3
+(3 rows)
+
+EXPLAIN (verbose, costs off) SELECT * FROM functest_sri2();
+          QUERY PLAN          
+------------------------------
+ Values Scan on "*VALUES*"
+   Output: "*VALUES*".column1
+(2 rows)
+
 -- Check behavior of VOID-returning SQL functions
 CREATE FUNCTION voidtest1(a int) RETURNS VOID LANGUAGE SQL AS
 $$ SELECT a + 1 $$;
@@ -360,7 +562,7 @@ SELECT * FROM voidtest5(3);
 
 -- Cleanup
 DROP SCHEMA temp_func_test CASCADE;
-NOTICE:  drop cascades to 21 other objects
+NOTICE:  drop cascades to 29 other objects
 DETAIL:  drop cascades to function functest_a_1(text,date)
 drop cascades to function functest_a_2(text[])
 drop cascades to function functest_a_3()
@@ -376,7 +578,15 @@ drop cascades to function functest_f_1(integer)
 drop cascades to function functest_f_2(integer)
 drop cascades to function functest_f_3(integer)
 drop cascades to function functest_f_4(integer)
+drop cascades to function functest_s_1(text,date)
+drop cascades to function functest_s_2(text[])
+drop cascades to function functest_s_3()
+drop cascades to function functest_s_3a()
+drop cascades to function functest_s_10(text,date)
+drop cascades to function functest_s_13()
 drop cascades to function functest_b_2(bigint)
+drop cascades to function functest_sri1()
+drop cascades to function functest_sri2()
 drop cascades to function voidtest1(integer)
 drop cascades to function voidtest2(integer,integer)
 drop cascades to function voidtest3(integer)
diff --git a/src/test/regress/expected/create_procedure.out b/src/test/regress/expected/create_procedure.out
index 3838fa2324..5d634570c4 100644
--- a/src/test/regress/expected/create_procedure.out
+++ b/src/test/regress/expected/create_procedure.out
@@ -65,6 +65,41 @@ SELECT * FROM cp_test ORDER BY b COLLATE "C";
  1 | xyzzy
 (3 rows)
 
+-- SQL-standard body
+CREATE PROCEDURE ptest1s(x text)
+LANGUAGE SQL
+BEGIN ATOMIC
+  INSERT INTO cp_test VALUES (1, x);
+END;
+\df ptest1s
+                        List of functions
+ Schema |  Name   | Result data type | Argument data types | Type 
+--------+---------+------------------+---------------------+------
+ public | ptest1s |                  | x text              | proc
+(1 row)
+
+SELECT pg_get_functiondef('ptest1s'::regproc);
+                 pg_get_functiondef                 
+----------------------------------------------------
+ CREATE OR REPLACE PROCEDURE public.ptest1s(x text)+
+  LANGUAGE sql                                     +
+ BEGIN ATOMIC                                      +
+  INSERT INTO cp_test (a, b)                       +
+    VALUES (1, x);                                 +
+ END                                               +
+ 
+(1 row)
+
+CALL ptest1s('b');
+SELECT * FROM cp_test ORDER BY b COLLATE "C";
+ a |   b   
+---+-------
+ 1 | 0
+ 1 | a
+ 1 | b
+ 1 | xyzzy
+(4 rows)
+
 CREATE PROCEDURE ptest2()
 LANGUAGE SQL
 AS $$
@@ -146,6 +181,28 @@ AS $$
 SELECT a = b;
 $$;
 CALL ptest7(least('a', 'b'), 'a');
+-- empty body
+CREATE PROCEDURE ptest8(x text)
+BEGIN ATOMIC
+END;
+\df ptest8
+                        List of functions
+ Schema |  Name  | Result data type | Argument data types | Type 
+--------+--------+------------------+---------------------+------
+ public | ptest8 |                  | x text              | proc
+(1 row)
+
+SELECT pg_get_functiondef('ptest8'::regproc);
+                pg_get_functiondef                 
+---------------------------------------------------
+ CREATE OR REPLACE PROCEDURE public.ptest8(x text)+
+  LANGUAGE sql                                    +
+ BEGIN ATOMIC                                     +
+ END                                              +
+ 
+(1 row)
+
+CALL ptest8('');
 -- OUT parameters
 CREATE PROCEDURE ptest9(OUT a int)
 LANGUAGE SQL
@@ -214,6 +271,7 @@ ALTER ROUTINE ptest1a RENAME TO ptest1;
 DROP ROUTINE cp_testfunc1(int);
 -- cleanup
 DROP PROCEDURE ptest1;
+DROP PROCEDURE ptest1s;
 DROP PROCEDURE ptest2;
 DROP TABLE cp_test;
 DROP USER regress_cp_user1;
diff --git a/src/test/regress/sql/create_function_3.sql b/src/test/regress/sql/create_function_3.sql
index bd108a918f..092e15b591 100644
--- a/src/test/regress/sql/create_function_3.sql
+++ b/src/test/regress/sql/create_function_3.sql
@@ -153,6 +153,65 @@ CREATE FUNCTION functest_F_4(int) RETURNS bool LANGUAGE 'sql'
 SELECT pg_get_functiondef('functest_F_2'::regproc);

+--
+-- SQL-standard body
+--
+CREATE FUNCTION functest_S_1(a text, b date) RETURNS boolean
+    LANGUAGE SQL
+    RETURN a = 'abcd' AND b > '2001-01-01';
+CREATE FUNCTION functest_S_2(a text[]) RETURNS int
+    RETURN a[1]::int;
+CREATE FUNCTION functest_S_3() RETURNS boolean
+    RETURN false;
+CREATE FUNCTION functest_S_3a() RETURNS boolean
+    BEGIN ATOMIC
+        RETURN false;
+    END;
+
+CREATE FUNCTION functest_S_10(a text, b date) RETURNS boolean
+    LANGUAGE SQL
+    BEGIN ATOMIC
+        SELECT a = 'abcd' AND b > '2001-01-01';
+    END;
+
+CREATE FUNCTION functest_S_13() RETURNS boolean
+    BEGIN ATOMIC
+        SELECT 1;
+        SELECT false;
+    END;
+
+-- polymorphic arguments not allowed in this form
+CREATE FUNCTION functest_S_xx(x anyarray) RETURNS anyelement
+    LANGUAGE SQL
+    RETURN x[1];
+
+SELECT functest_S_1('abcd', '2020-01-01');
+SELECT functest_S_2(ARRAY['1', '2', '3']);
+SELECT functest_S_3();
+
+SELECT functest_S_10('abcd', '2020-01-01');
+SELECT functest_S_13();
+
+SELECT pg_get_functiondef('functest_S_1'::regproc);
+SELECT pg_get_functiondef('functest_S_2'::regproc);
+SELECT pg_get_functiondef('functest_S_3'::regproc);
+SELECT pg_get_functiondef('functest_S_3a'::regproc);
+SELECT pg_get_functiondef('functest_S_10'::regproc);
+SELECT pg_get_functiondef('functest_S_13'::regproc);
+
+-- test with views
+CREATE TABLE functest3 (a int);
+INSERT INTO functest3 VALUES (1), (2);
+CREATE VIEW functestv3 AS SELECT * FROM functest3;
+
+CREATE FUNCTION functest_S_14() RETURNS bigint
+    RETURN (SELECT count(*) FROM functestv3);
+
+SELECT functest_S_14();
+
+DROP TABLE functest3 CASCADE;
+
+
 -- information_schema tests
 
 CREATE FUNCTION functest_IS_1(a int, b int default 1, c text default 'foo')
@@ -177,6 +236,23 @@ CREATE FUNCTION functest_IS_3(a int default 1, out b int)
 
 DROP FUNCTION functest_IS_1(int, int, text), functest_IS_2(int), functest_IS_3(int);
 
+CREATE TABLE functest1 (a int, b int);
+CREATE SEQUENCE functest2;
+
+CREATE FUNCTION functest_IS_4()
+    RETURNS int
+    LANGUAGE SQL
+    RETURN (SELECT count(a) FROM functest1);
+
+CREATE FUNCTION functest_IS_5()
+    RETURNS int
+    LANGUAGE SQL
+    RETURN nextval('functest2');
+
+DROP TABLE functest1 CASCADE;
+DROP SEQUENCE functest2 CASCADE;
+
+
 -- overload
 CREATE FUNCTION functest_B_2(bigint) RETURNS bool LANGUAGE 'sql'
        IMMUTABLE AS 'SELECT $1 > 0';
@@ -194,6 +270,29 @@ CREATE OR REPLACE PROCEDURE functest1(a int) LANGUAGE SQL AS 'SELECT $1';
 DROP FUNCTION functest1(a int);

+-- inlining of set-returning functions
+
+CREATE FUNCTION functest_sri1() RETURNS SETOF int
+LANGUAGE SQL
+STABLE
+AS '
+    VALUES (1), (2), (3);
+';
+
+SELECT * FROM functest_sri1();
+EXPLAIN (verbose, costs off) SELECT * FROM functest_sri1();
+
+CREATE FUNCTION functest_sri2() RETURNS SETOF int
+LANGUAGE SQL
+STABLE
+BEGIN ATOMIC
+    VALUES (1), (2), (3);
+END;
+
+SELECT * FROM functest_sri2();
+EXPLAIN (verbose, costs off) SELECT * FROM functest_sri2();
+
+
 -- Check behavior of VOID-returning SQL functions
 
 CREATE FUNCTION voidtest1(a int) RETURNS VOID LANGUAGE SQL AS
diff --git a/src/test/regress/sql/create_procedure.sql b/src/test/regress/sql/create_procedure.sql
index 2ef1c82cea..8c0d70cb16 100644
--- a/src/test/regress/sql/create_procedure.sql
+++ b/src/test/regress/sql/create_procedure.sql
@@ -28,6 +28,21 @@ CREATE PROCEDURE ptest1(x text)
 SELECT * FROM cp_test ORDER BY b COLLATE "C";

+-- SQL-standard body
+CREATE PROCEDURE ptest1s(x text)
+LANGUAGE SQL
+BEGIN ATOMIC
+  INSERT INTO cp_test VALUES (1, x);
+END;
+
+\df ptest1s
+SELECT pg_get_functiondef('ptest1s'::regproc);
+
+CALL ptest1s('b');
+
+SELECT * FROM cp_test ORDER BY b COLLATE "C";
+
+
 CREATE PROCEDURE ptest2()
 LANGUAGE SQL
 AS $$
@@ -112,6 +127,16 @@ CREATE PROCEDURE ptest7(a text, b text)
 CALL ptest7(least('a', 'b'), 'a');

+-- empty body
+CREATE PROCEDURE ptest8(x text)
+BEGIN ATOMIC
+END;
+
+\df ptest8
+SELECT pg_get_functiondef('ptest8'::regproc);
+CALL ptest8('');
+
+
 -- OUT parameters
 
 CREATE PROCEDURE ptest9(OUT a int)
@@ -170,6 +195,7 @@ CREATE USER regress_cp_user1;
 -- cleanup
 
 DROP PROCEDURE ptest1;
+DROP PROCEDURE ptest1s;
 DROP PROCEDURE ptest2;
 
 DROP TABLE cp_test;

base-commit: 2f0760c9ff827bb3d23ee327e6b46038000c7ef9
-- 
2.28.0

--------------AC3B021D8F5CFCF564639AE4--