pgsql: Update pg_stat_statements extension for parallel query.

diff --git a/contrib/pg_stat_statements/pg_stat_statements--1.3--1.4.sql b/contrib/pg_stat_statements/pg_stat_statements--1.3--1.4.sql
index ae70c1f..fd54aa8 100644
--- a/contrib/pg_stat_statements/pg_stat_statements--1.3--1.4.sql
+++ b/contrib/pg_stat_statements/pg_stat_statements--1.3--1.4.sql
@@ -3,5 +3,52 @@
 -- complain if script is sourced in psql, rather than via ALTER EXTENSION
 \echo Use "ALTER EXTENSION pg_stat_statements UPDATE TO '1.4'" to load this file. \quit
 
+/* First we have to remove them from the extension */
+ALTER EXTENSION pg_stat_statements DROP VIEW pg_stat_statements;
+ALTER EXTENSION pg_stat_statements DROP FUNCTION pg_stat_statements(boolean);
+
+/* Then we can drop them */
+DROP VIEW pg_stat_statements;
+DROP FUNCTION pg_stat_statements(boolean);
+
+/* Now redefine */
+CREATE FUNCTION pg_stat_statements(IN showtext boolean,
+    OUT userid oid,
+    OUT dbid oid,
+    OUT queryid bigint,
+    OUT query text,
+    OUT calls int8,
+    OUT total_time float8,
+    OUT min_time float8,
+    OUT max_time float8,
+    OUT mean_time float8,
+    OUT stddev_time float8,
+    OUT rows int8,
+    OUT shared_blks_hit int8,
+    OUT shared_blks_read int8,
+    OUT shared_blks_dirtied int8,
+    OUT shared_blks_written int8,
+    OUT local_blks_hit int8,
+    OUT local_blks_read int8,
+    OUT local_blks_dirtied int8,
+    OUT local_blks_written int8,
+    OUT temp_blks_read int8,
+    OUT temp_blks_written int8,
+    OUT blk_read_time float8,
+    OUT blk_write_time float8
+)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'pg_stat_statements_1_4'
+LANGUAGE C STRICT VOLATILE PARALLEL SAFE;
+
+CREATE VIEW pg_stat_statements AS
+  SELECT * FROM pg_stat_statements(true);
+
+GRANT SELECT ON pg_stat_statements TO PUBLIC;
+
+/*
+ * Given the general prohibition against write operations in parallel queries,
+ * it is perhaps a bit surprising that pg_stat_statements_reset() is parallel
+ * safe.  But since it only modifies shared memory, not the database, it's OK.
+ */
 ALTER FUNCTION pg_stat_statements_reset() PARALLEL SAFE;
-ALTER FUNCTION pg_stat_statements(boolean) PARALLEL SAFE;
diff --git a/contrib/pg_stat_statements/pg_stat_statements--1.4.sql b/contrib/pg_stat_statements/pg_stat_statements--1.4.sql
index 58cdf60..86bfb6b 100644
--- a/contrib/pg_stat_statements/pg_stat_statements--1.4.sql
+++ b/contrib/pg_stat_statements/pg_stat_statements--1.4.sql
@@ -35,7 +35,7 @@ CREATE FUNCTION pg_stat_statements(IN showtext boolean,
     OUT blk_write_time float8
 )
 RETURNS SETOF record
-AS 'MODULE_PATHNAME', 'pg_stat_statements_1_3'
+AS 'MODULE_PATHNAME', 'pg_stat_statements_1_4'
 LANGUAGE C STRICT VOLATILE PARALLEL SAFE;
 
 -- Register a view on the function for ease of use.
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
index 3d9b8e4..552ffb8 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -117,7 +117,8 @@ typedef enum pgssVersion
 	PGSS_V1_0 = 0,
 	PGSS_V1_1,
 	PGSS_V1_2,
-	PGSS_V1_3
+	PGSS_V1_3,
+	PGSS_V1_4
 } pgssVersion;
 
 /*
@@ -281,6 +282,7 @@ void		_PG_fini(void);
 PG_FUNCTION_INFO_V1(pg_stat_statements_reset);
 PG_FUNCTION_INFO_V1(pg_stat_statements_1_2);
 PG_FUNCTION_INFO_V1(pg_stat_statements_1_3);
+PG_FUNCTION_INFO_V1(pg_stat_statements_1_4);
 PG_FUNCTION_INFO_V1(pg_stat_statements);
 
 static void pgss_shmem_startup(void);
@@ -1282,6 +1284,7 @@ pg_stat_statements_reset(PG_FUNCTION_ARGS)
 #define PG_STAT_STATEMENTS_COLS_V1_1	18
 #define PG_STAT_STATEMENTS_COLS_V1_2	19
 #define PG_STAT_STATEMENTS_COLS_V1_3	23
+#define PG_STAT_STATEMENTS_COLS_V1_4	23		/* only parallel safety was changed */
 #define PG_STAT_STATEMENTS_COLS			23		/* maximum of above */
 
 /*
@@ -1295,6 +1298,16 @@ pg_stat_statements_reset(PG_FUNCTION_ARGS)
  * function.  Unfortunately we weren't bright enough to do that for 1.1.
  */
 Datum
+pg_stat_statements_1_4(PG_FUNCTION_ARGS)
+{
+	bool		showtext = PG_GETARG_BOOL(0);
+
+	pg_stat_statements_internal(fcinfo, PGSS_V1_4, showtext);
+
+	return (Datum) 0;
+}
+
+Datum
 pg_stat_statements_1_3(PG_FUNCTION_ARGS)
 {
 	bool		showtext = PG_GETARG_BOOL(0);
@@ -1393,8 +1406,9 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 			if (api_version != PGSS_V1_2)
 				elog(ERROR, "incorrect number of output arguments");
 			break;
-		case PG_STAT_STATEMENTS_COLS_V1_3:
-			if (api_version != PGSS_V1_3)
+		case PG_STAT_STATEMENTS_COLS_V1_3 || PG_STAT_STATEMENTS_COLS_V1_4:
+			/* version 1.4 only changed parallel safety */
+			if ((api_version != PGSS_V1_3) || (api_version != PGSS_V1_4))
 				elog(ERROR, "incorrect number of output arguments");
 			break;
 		default:
@@ -1598,6 +1612,7 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 					 api_version == PGSS_V1_1 ? PG_STAT_STATEMENTS_COLS_V1_1 :
 					 api_version == PGSS_V1_2 ? PG_STAT_STATEMENTS_COLS_V1_2 :
 					 api_version == PGSS_V1_3 ? PG_STAT_STATEMENTS_COLS_V1_3 :
+					 api_version == PGSS_V1_4 ? PG_STAT_STATEMENTS_COLS_V1_4 :
 					 -1 /* fail if you forget to update this assert */ ));
 
 		tuplestore_putvalues(tupstore, tupdesc, values, nulls);