From c7a407143d1283a6b86c3244efccf0da7990e330 Mon Sep 17 00:00:00 2001
From: Julien Rouhaud <julien.rouhaud@free.fr>
Date: Wed, 27 Mar 2019 11:24:35 +0100
Subject: [PATCH 2/2] Add planning counters to pg_stat_statements

---
 contrib/pg_stat_statements/Makefile           |   3 +-
 .../expected/pg_stat_statements.out           |  64 ++++
 .../pg_stat_statements--1.7--1.8.sql          |  52 ++++
 .../pg_stat_statements/pg_stat_statements.c   | 293 +++++++++++++-----
 .../pg_stat_statements.control                |   2 +-
 .../sql/pg_stat_statements.sql                |  16 +
 doc/src/sgml/pgstatstatements.sgml            |  49 ++-
 7 files changed, 401 insertions(+), 78 deletions(-)
 create mode 100644 contrib/pg_stat_statements/pg_stat_statements--1.7--1.8.sql

diff --git a/contrib/pg_stat_statements/Makefile b/contrib/pg_stat_statements/Makefile
index 051ce46f0c..db33d9ffe1 100644
--- a/contrib/pg_stat_statements/Makefile
+++ b/contrib/pg_stat_statements/Makefile
@@ -4,7 +4,8 @@ MODULE_big = pg_stat_statements
 OBJS = pg_stat_statements.o $(WIN32RES)
 
 EXTENSION = pg_stat_statements
-DATA = pg_stat_statements--1.4.sql pg_stat_statements--1.6--1.7.sql \
+DATA = pg_stat_statements--1.4.sql \
+    pg_stat_statements--1.7--1.8.sql pg_stat_statements--1.6--1.7.sql \
 	pg_stat_statements--1.5--1.6.sql pg_stat_statements--1.4--1.5.sql \
 	pg_stat_statements--1.3--1.4.sql pg_stat_statements--1.2--1.3.sql \
 	pg_stat_statements--1.1--1.2.sql pg_stat_statements--1.0--1.1.sql \
diff --git a/contrib/pg_stat_statements/expected/pg_stat_statements.out b/contrib/pg_stat_statements/expected/pg_stat_statements.out
index c759763be2..8517b124e4 100644
--- a/contrib/pg_stat_statements/expected/pg_stat_statements.out
+++ b/contrib/pg_stat_statements/expected/pg_stat_statements.out
@@ -593,4 +593,68 @@ SELECT query, calls, rows FROM pg_stat_statements ORDER BY query COLLATE "C";
 --
 DROP ROLE regress_stats_user1;
 DROP ROLE regress_stats_user2;
+--
+-- [re]plan counting
+--
+SELECT pg_stat_statements_reset();
+ pg_stat_statements_reset 
+--------------------------
+ 
+(1 row)
+
+CREATE TABLE test ();
+PREPARE prep1 AS SELECT COUNT(*) FROM test;;
+EXECUTE prep1;
+ count 
+-------
+     0
+(1 row)
+
+EXECUTE prep1;
+ count 
+-------
+     0
+(1 row)
+
+EXECUTE prep1;
+ count 
+-------
+     0
+(1 row)
+
+ALTER TABLE test ADD COLUMN x int;
+EXECUTE prep1;
+ count 
+-------
+     0
+(1 row)
+
+SELECT 42;
+ ?column? 
+----------
+       42
+(1 row)
+
+SELECT 42;
+ ?column? 
+----------
+       42
+(1 row)
+
+SELECT 42;
+ ?column? 
+----------
+       42
+(1 row)
+
+SELECT query, plans, calls, rows FROM pg_stat_statements ORDER BY query COLLATE "C";
+                   query                    | plans | calls | rows 
+--------------------------------------------+-------+-------+------
+ ALTER TABLE test ADD COLUMN x int          |     0 |     1 |    0
+ CREATE TABLE test ()                       |     0 |     1 |    0
+ PREPARE prep1 AS SELECT COUNT(*) FROM test |     2 |     4 |    4
+ SELECT $1                                  |     3 |     3 |    3
+ SELECT pg_stat_statements_reset()          |     0 |     1 |    1
+(5 rows)
+
 DROP EXTENSION pg_stat_statements;
diff --git a/contrib/pg_stat_statements/pg_stat_statements--1.7--1.8.sql b/contrib/pg_stat_statements/pg_stat_statements--1.7--1.8.sql
new file mode 100644
index 0000000000..de75643928
--- /dev/null
+++ b/contrib/pg_stat_statements/pg_stat_statements--1.7--1.8.sql
@@ -0,0 +1,52 @@
+/* contrib/pg_stat_statements/pg_stat_statements--1.7--1.8.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION pg_stat_statements UPDATE TO '1.8'" 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 plans int8,
+    OUT total_plan_time float8,
+    OUT calls int8,
+    OUT total_exec_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_8'
+LANGUAGE C STRICT VOLATILE PARALLEL SAFE;
+
+CREATE VIEW pg_stat_statements AS
+  SELECT *, total_plan_time + total_exec_time AS total_time
+    FROM pg_stat_statements(true);
+
+GRANT SELECT ON pg_stat_statements TO PUBLIC;
+
+
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
index 490ade9e5f..059d283fd5 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -1,7 +1,8 @@
 /*-------------------------------------------------------------------------
  *
  * pg_stat_statements.c
- *		Track statement execution times across a whole database cluster.
+ *		Track statement planning and execution times as well as resources
+ *      consumption (like block reads, ...) across a whole cluster.
  *
  * Execution costs are totalled for each distinct source query, and kept in
  * a shared hashtable.  (We track only as many distinct queries as will fit
@@ -66,6 +67,7 @@
 #include "funcapi.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "optimizer/planner.h"
 #include "parser/analyze.h"
 #include "parser/parsetree.h"
 #include "parser/scanner.h"
@@ -120,9 +122,17 @@ typedef enum pgssVersion
 	PGSS_V1_0 = 0,
 	PGSS_V1_1,
 	PGSS_V1_2,
-	PGSS_V1_3
+	PGSS_V1_3,
+	PGSS_V1_8
 } pgssVersion;
 
+typedef enum pgssStoreKind
+{
+	PGSS_JUMBLE,
+	PGSS_EXEC_TIME,
+	PGSS_PLAN_TIME
+}	pgssStoreKind;
+
 /*
  * Hashtable key that defines the identity of a hashtable entry.  We separate
  * queries by user and by database even if they are otherwise identical.
@@ -145,11 +155,13 @@ typedef struct pgssHashKey
 typedef struct Counters
 {
 	int64		calls;			/* # of times executed */
-	double		total_time;		/* total execution time, in msec */
+	double		total_exec_time;	/* total execution time, in msec */
 	double		min_time;		/* minimum execution time in msec */
 	double		max_time;		/* maximum execution time in msec */
 	double		mean_time;		/* mean execution time in msec */
 	double		sum_var_time;	/* sum of variances in execution time in msec */
+	int64		plans;			/* # of times planned */
+	double		total_plan_time;	/* total planning time, in msec */
 	int64		rows;			/* total # of retrieved or affected rows */
 	int64		shared_blks_hit;	/* # of shared buffer hits */
 	int64		shared_blks_read;	/* # of shared disk blocks read */
@@ -238,6 +250,7 @@ static int	nested_level = 0;
 
 /* Saved hook values in case of unload */
 static shmem_startup_hook_type prev_shmem_startup_hook = NULL;
+static planner_hook_type prev_planner_hook = NULL;
 static post_parse_analyze_hook_type prev_post_parse_analyze_hook = NULL;
 static ExecutorStart_hook_type prev_ExecutorStart = NULL;
 static ExecutorRun_hook_type prev_ExecutorRun = NULL;
@@ -268,6 +281,7 @@ static const struct config_enum_entry track_options[] =
 
 static int	pgss_max;			/* max # statements to track */
 static int	pgss_track;			/* tracking level */
+static bool pgss_track_planning;	/* whether to track planning duration */
 static bool pgss_track_utility; /* whether to track utility commands */
 static bool pgss_save;			/* whether to save stats across shutdown */
 
@@ -293,10 +307,15 @@ PG_FUNCTION_INFO_V1(pg_stat_statements_reset);
 PG_FUNCTION_INFO_V1(pg_stat_statements_reset_1_7);
 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_8);
 PG_FUNCTION_INFO_V1(pg_stat_statements);
 
 static void pgss_shmem_startup(void);
 static void pgss_shmem_shutdown(int code, Datum arg);
+static PlannedStmt *pgss_planner_hook(Query *parse,
+									  const char *query_text,
+									  int cursorOptions,
+									  ParamListInfo boundParams);
 static void pgss_post_parse_analyze(ParseState *pstate, Query *query);
 static void pgss_ExecutorStart(QueryDesc *queryDesc, int eflags);
 static void pgss_ExecutorRun(QueryDesc *queryDesc,
@@ -311,7 +330,9 @@ static void pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
 static uint64 pgss_hash_string(const char *str, int len);
 static void pgss_store(const char *query, uint64 queryId,
 					   int query_location, int query_len,
-					   double total_time, uint64 rows,
+					   pgssStoreKind kind,
+					   double timing,
+					   uint64 rows,
 					   const BufferUsage *bufusage,
 					   pgssJumbleState *jstate);
 static void pg_stat_statements_internal(FunctionCallInfo fcinfo,
@@ -340,6 +361,7 @@ static char *generate_normalized_query(pgssJumbleState *jstate, const char *quer
 static void fill_in_constant_lengths(pgssJumbleState *jstate, const char *query,
 									 int query_loc);
 static int	comp_location(const void *a, const void *b);
+static BufferUsage compute_buffer_counters(BufferUsage start, BufferUsage stop);
 
 
 /*
@@ -398,6 +420,17 @@ _PG_init(void)
 							 NULL,
 							 NULL);
 
+	DefineCustomBoolVariable("pg_stat_statements.track_planning",
+							 "Selects whether planning duration is tracked by pg_stat_statements.",
+							 NULL,
+							 &pgss_track_planning,
+							 true,
+							 PGC_SUSET,
+							 0,
+							 NULL,
+							 NULL,
+							 NULL);
+
 	DefineCustomBoolVariable("pg_stat_statements.save",
 							 "Save pg_stat_statements statistics across server shutdowns.",
 							 NULL,
@@ -424,6 +457,8 @@ _PG_init(void)
 	 */
 	prev_shmem_startup_hook = shmem_startup_hook;
 	shmem_startup_hook = pgss_shmem_startup;
+	prev_planner_hook = planner_hook;
+	planner_hook = pgss_planner_hook;
 	prev_post_parse_analyze_hook = post_parse_analyze_hook;
 	post_parse_analyze_hook = pgss_post_parse_analyze;
 	prev_ExecutorStart = ExecutorStart_hook;
@@ -447,6 +482,7 @@ _PG_fini(void)
 	/* Uninstall hooks. */
 	shmem_startup_hook = prev_shmem_startup_hook;
 	post_parse_analyze_hook = prev_post_parse_analyze_hook;
+	planner_hook = prev_planner_hook;
 	ExecutorStart_hook = prev_ExecutorStart;
 	ExecutorRun_hook = prev_ExecutorRun;
 	ExecutorFinish_hook = prev_ExecutorFinish;
@@ -837,12 +873,86 @@ pgss_post_parse_analyze(ParseState *pstate, Query *query)
 				   query->queryId,
 				   query->stmt_location,
 				   query->stmt_len,
+				   PGSS_JUMBLE,
 				   0,
 				   0,
 				   NULL,
 				   &jstate);
 }
 
+/*
+ * Planner hook: forward to regular planner, but measure planning time.
+ */
+static PlannedStmt *
+pgss_planner_hook(Query *parse,
+				  const char *query_text,
+				  int cursorOptions,
+				  ParamListInfo boundParams)
+{
+	PlannedStmt *result;
+	BufferUsage bufusage_start,
+				bufusage;
+
+	bufusage_start = pgBufferUsage;
+	if (pgss_enabled() && pgss_track_planning)
+	{
+		instr_time	start;
+		instr_time	duration;
+
+		INSTR_TIME_SET_CURRENT(start);
+
+		nested_level++;
+		PG_TRY();
+		{
+			if (prev_planner_hook)
+				result = prev_planner_hook(parse, query_text, cursorOptions,
+										   boundParams);
+			else
+				result = standard_planner(parse, query_text, cursorOptions,
+										   boundParams);
+			nested_level--;
+		}
+		PG_CATCH();
+		{
+			nested_level--;
+			PG_RE_THROW();
+		}
+		PG_END_TRY();
+
+		INSTR_TIME_SET_CURRENT(duration);
+		INSTR_TIME_SUBTRACT(duration, start);
+
+		/* calc differences of buffer counters. */
+		bufusage = compute_buffer_counters(bufusage_start, pgBufferUsage);
+
+		/*
+		 * we only store planning duration, query text has been initialized
+		 * during previous pgss_post_parse_analyze as it not available inside
+		 * pgss_planner_hook.
+		 */
+		pgss_store(query_text,
+				   parse->queryId,
+				   parse->stmt_location,
+				   parse->stmt_len,
+				   PGSS_PLAN_TIME,
+				   INSTR_TIME_GET_MILLISEC(duration),
+				   0,
+				   &bufusage,
+				   NULL);
+	}
+	else
+	{
+		if (prev_planner_hook)
+			result = prev_planner_hook(parse, query_text, cursorOptions,
+									   boundParams);
+		else
+			result = standard_planner(parse, query_text, cursorOptions,
+									   boundParams);
+	}
+
+	return result;
+}
+
 /*
  * ExecutorStart hook: start up tracking if needed
  */
@@ -944,6 +1054,7 @@ pgss_ExecutorEnd(QueryDesc *queryDesc)
 				   queryId,
 				   queryDesc->plannedstmt->stmt_location,
 				   queryDesc->plannedstmt->stmt_len,
+				   PGSS_EXEC_TIME,
 				   queryDesc->totaltime->total * 1000.0,	/* convert to msec */
 				   queryDesc->estate->es_processed,
 				   &queryDesc->totaltime->bufusage,
@@ -1026,35 +1137,13 @@ pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
 			rows = 0;
 
 		/* calc differences of buffer counters. */
-		bufusage.shared_blks_hit =
-			pgBufferUsage.shared_blks_hit - bufusage_start.shared_blks_hit;
-		bufusage.shared_blks_read =
-			pgBufferUsage.shared_blks_read - bufusage_start.shared_blks_read;
-		bufusage.shared_blks_dirtied =
-			pgBufferUsage.shared_blks_dirtied - bufusage_start.shared_blks_dirtied;
-		bufusage.shared_blks_written =
-			pgBufferUsage.shared_blks_written - bufusage_start.shared_blks_written;
-		bufusage.local_blks_hit =
-			pgBufferUsage.local_blks_hit - bufusage_start.local_blks_hit;
-		bufusage.local_blks_read =
-			pgBufferUsage.local_blks_read - bufusage_start.local_blks_read;
-		bufusage.local_blks_dirtied =
-			pgBufferUsage.local_blks_dirtied - bufusage_start.local_blks_dirtied;
-		bufusage.local_blks_written =
-			pgBufferUsage.local_blks_written - bufusage_start.local_blks_written;
-		bufusage.temp_blks_read =
-			pgBufferUsage.temp_blks_read - bufusage_start.temp_blks_read;
-		bufusage.temp_blks_written =
-			pgBufferUsage.temp_blks_written - bufusage_start.temp_blks_written;
-		bufusage.blk_read_time = pgBufferUsage.blk_read_time;
-		INSTR_TIME_SUBTRACT(bufusage.blk_read_time, bufusage_start.blk_read_time);
-		bufusage.blk_write_time = pgBufferUsage.blk_write_time;
-		INSTR_TIME_SUBTRACT(bufusage.blk_write_time, bufusage_start.blk_write_time);
+		bufusage = compute_buffer_counters(bufusage_start, pgBufferUsage);
 
 		pgss_store(queryString,
 				   0,			/* signal that it's a utility stmt */
 				   pstmt->stmt_location,
 				   pstmt->stmt_len,
+				   PGSS_EXEC_TIME,
 				   INSTR_TIME_GET_MILLISEC(duration),
 				   rows,
 				   &bufusage,
@@ -1093,12 +1182,14 @@ pgss_hash_string(const char *str, int len)
  *
  * If jstate is not NULL then we're trying to create an entry for which
  * we have no statistics as yet; we just want to record the normalized
- * query string.  total_time, rows, bufusage are ignored in this case.
+ * query string.  total_exec_time, rows, bufusage are ignored in this case.
  */
 static void
 pgss_store(const char *query, uint64 queryId,
 		   int query_location, int query_len,
-		   double total_time, uint64 rows,
+		   pgssStoreKind kind,
+		   double timing,
+		   uint64 rows,
 		   const BufferUsage *bufusage,
 		   pgssJumbleState *jstate)
 {
@@ -1186,8 +1277,10 @@ pgss_store(const char *query, uint64 queryId,
 		 * in the interval where we don't hold the lock below.  That case is
 		 * handled by entry_alloc.)
 		 */
-		if (jstate)
+		if (kind == PGSS_JUMBLE)
 		{
+			Assert(jstate);
+
 			LWLockRelease(pgss->lock);
 			norm_query = generate_normalized_query(jstate, query,
 												   query_location,
@@ -1236,7 +1329,7 @@ pgss_store(const char *query, uint64 queryId,
 	}
 
 	/* Increment the counts, except when jstate is not NULL */
-	if (!jstate)
+	if (kind != PGSS_JUMBLE)
 	{
 		/*
 		 * Grab the spinlock while updating the counters (see comment about
@@ -1250,47 +1343,58 @@ pgss_store(const char *query, uint64 queryId,
 		if (e->counters.calls == 0)
 			e->counters.usage = USAGE_INIT;
 
-		e->counters.calls += 1;
-		e->counters.total_time += total_time;
-		if (e->counters.calls == 1)
+		if (kind == PGSS_EXEC_TIME)
 		{
-			e->counters.min_time = total_time;
-			e->counters.max_time = total_time;
-			e->counters.mean_time = total_time;
+			/* updating counters for executions */
+			e->counters.calls += 1;
+			e->counters.total_exec_time += timing;
+
+			if (e->counters.calls == 1)
+			{
+				e->counters.min_time = timing;
+				e->counters.max_time = timing;
+				e->counters.mean_time = timing;
+			}
+			else
+			{
+				/*
+				 * Welford's method for accurately computing variance. See
+				 * <http://www.johndcook.com/blog/standard_deviation/>
+				 */
+				double		old_mean = e->counters.mean_time;
+
+				e->counters.mean_time +=
+					(timing - old_mean) / e->counters.calls;
+				e->counters.sum_var_time +=
+					(timing - old_mean) * (timing - e->counters.mean_time);
+
+				/* calculate min and max time */
+				if (e->counters.min_time > timing)
+					e->counters.min_time = timing;
+				if (e->counters.max_time < timing)
+					e->counters.max_time = timing;
+			}
+			e->counters.rows += rows;
+			e->counters.shared_blks_hit += bufusage->shared_blks_hit;
+			e->counters.shared_blks_read += bufusage->shared_blks_read;
+			e->counters.shared_blks_dirtied += bufusage->shared_blks_dirtied;
+			e->counters.shared_blks_written += bufusage->shared_blks_written;
+			e->counters.local_blks_hit += bufusage->local_blks_hit;
+			e->counters.local_blks_read += bufusage->local_blks_read;
+			e->counters.local_blks_dirtied += bufusage->local_blks_dirtied;
+			e->counters.local_blks_written += bufusage->local_blks_written;
+			e->counters.temp_blks_read += bufusage->temp_blks_read;
+			e->counters.temp_blks_written += bufusage->temp_blks_written;
+			e->counters.blk_read_time += INSTR_TIME_GET_MILLISEC(bufusage->blk_read_time);
+			e->counters.blk_write_time += INSTR_TIME_GET_MILLISEC(bufusage->blk_write_time);
+			e->counters.usage += USAGE_EXEC(total_exec_time);
 		}
 		else
 		{
-			/*
-			 * Welford's method for accurately computing variance. See
-			 * <http://www.johndcook.com/blog/standard_deviation/>
-			 */
-			double		old_mean = e->counters.mean_time;
-
-			e->counters.mean_time +=
-				(total_time - old_mean) / e->counters.calls;
-			e->counters.sum_var_time +=
-				(total_time - old_mean) * (total_time - e->counters.mean_time);
-
-			/* calculate min and max time */
-			if (e->counters.min_time > total_time)
-				e->counters.min_time = total_time;
-			if (e->counters.max_time < total_time)
-				e->counters.max_time = total_time;
+			/* updating counters for planning */
+			e->counters.plans += 1;
+			e->counters.total_plan_time += timing;
 		}
-		e->counters.rows += rows;
-		e->counters.shared_blks_hit += bufusage->shared_blks_hit;
-		e->counters.shared_blks_read += bufusage->shared_blks_read;
-		e->counters.shared_blks_dirtied += bufusage->shared_blks_dirtied;
-		e->counters.shared_blks_written += bufusage->shared_blks_written;
-		e->counters.local_blks_hit += bufusage->local_blks_hit;
-		e->counters.local_blks_read += bufusage->local_blks_read;
-		e->counters.local_blks_dirtied += bufusage->local_blks_dirtied;
-		e->counters.local_blks_written += bufusage->local_blks_written;
-		e->counters.temp_blks_read += bufusage->temp_blks_read;
-		e->counters.temp_blks_written += bufusage->temp_blks_written;
-		e->counters.blk_read_time += INSTR_TIME_GET_MILLISEC(bufusage->blk_read_time);
-		e->counters.blk_write_time += INSTR_TIME_GET_MILLISEC(bufusage->blk_write_time);
-		e->counters.usage += USAGE_EXEC(total_time);
 
 		SpinLockRelease(&e->mutex);
 	}
@@ -1338,7 +1442,8 @@ 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			23	/* maximum of above */
+#define PG_STAT_STATEMENTS_COLS_V1_8	25
+#define PG_STAT_STATEMENTS_COLS			25	/* maximum of above */
 
 /*
  * Retrieve statement statistics.
@@ -1350,6 +1455,16 @@ pg_stat_statements_reset(PG_FUNCTION_ARGS)
  * expected API version is identified by embedding it in the C name of the
  * function.  Unfortunately we weren't bright enough to do that for 1.1.
  */
+Datum
+pg_stat_statements_1_8(PG_FUNCTION_ARGS)
+{
+	bool		showtext = PG_GETARG_BOOL(0);
+
+	pg_stat_statements_internal(fcinfo, PGSS_V1_8, showtext);
+
+	return (Datum) 0;
+}
+
 Datum
 pg_stat_statements_1_3(PG_FUNCTION_ARGS)
 {
@@ -1456,6 +1571,10 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 			if (api_version != PGSS_V1_3)
 				elog(ERROR, "incorrect number of output arguments");
 			break;
+		case PG_STAT_STATEMENTS_COLS_V1_8:
+			if (api_version != PGSS_V1_8)
+				elog(ERROR, "incorrect number of output arguments");
+			break;
 		default:
 			elog(ERROR, "incorrect number of output arguments");
 	}
@@ -1614,8 +1733,13 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 		if (tmp.calls == 0)
 			continue;
 
+		if (api_version >= PGSS_V1_8)
+		{
+			values[i++] = Int64GetDatumFast(tmp.plans);
+			values[i++] = Float8GetDatumFast(tmp.total_plan_time);
+		}
 		values[i++] = Int64GetDatumFast(tmp.calls);
-		values[i++] = Float8GetDatumFast(tmp.total_time);
+		values[i++] = Float8GetDatumFast(tmp.total_exec_time);
 		if (api_version >= PGSS_V1_3)
 		{
 			values[i++] = Float8GetDatumFast(tmp.min_time);
@@ -1657,6 +1781,7 @@ 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_8 ? PG_STAT_STATEMENTS_COLS_V1_8 :
 					 -1 /* fail if you forget to update this assert */ ));
 
 		tuplestore_putvalues(tupstore, tupdesc, values, nulls);
@@ -3243,3 +3368,31 @@ comp_location(const void *a, const void *b)
 	else
 		return 0;
 }
+
+static BufferUsage
+compute_buffer_counters(BufferUsage start, BufferUsage stop)
+{
+	BufferUsage result;
+
+	result.shared_blks_hit = stop.shared_blks_hit - start.shared_blks_hit;
+	result.shared_blks_read = stop.shared_blks_read - start.shared_blks_read;
+	result.shared_blks_dirtied = stop.shared_blks_dirtied -
+		start.shared_blks_dirtied;
+	result.shared_blks_written = stop.shared_blks_written -
+		start.shared_blks_written;
+	result.local_blks_hit = stop.local_blks_hit - start.local_blks_hit;
+	result.local_blks_read = stop.local_blks_read - start.local_blks_read;
+	result.local_blks_dirtied = stop.local_blks_dirtied -
+		start.local_blks_dirtied;
+	result.local_blks_written = stop.local_blks_written -
+		start.local_blks_written;
+	result.temp_blks_read = stop.temp_blks_read - start.temp_blks_read;
+	result.temp_blks_written = stop.temp_blks_written -
+		start.temp_blks_written;
+	result.blk_read_time = stop.blk_read_time;
+	INSTR_TIME_SUBTRACT(result.blk_read_time, start.blk_read_time);
+	result.blk_write_time = stop.blk_write_time;
+	INSTR_TIME_SUBTRACT(result.blk_write_time, start.blk_write_time);
+
+	return result;
+}
diff --git a/contrib/pg_stat_statements/pg_stat_statements.control b/contrib/pg_stat_statements/pg_stat_statements.control
index 14cb422354..7fb20df886 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.control
+++ b/contrib/pg_stat_statements/pg_stat_statements.control
@@ -1,5 +1,5 @@
 # pg_stat_statements extension
 comment = 'track execution statistics of all SQL statements executed'
-default_version = '1.7'
+default_version = '1.8'
 module_pathname = '$libdir/pg_stat_statements'
 relocatable = true
diff --git a/contrib/pg_stat_statements/sql/pg_stat_statements.sql b/contrib/pg_stat_statements/sql/pg_stat_statements.sql
index aef890d893..4d7d6e584d 100644
--- a/contrib/pg_stat_statements/sql/pg_stat_statements.sql
+++ b/contrib/pg_stat_statements/sql/pg_stat_statements.sql
@@ -259,4 +259,20 @@ SELECT query, calls, rows FROM pg_stat_statements ORDER BY query COLLATE "C";
 DROP ROLE regress_stats_user1;
 DROP ROLE regress_stats_user2;
 
+--
+-- [re]plan counting
+--
+SELECT pg_stat_statements_reset();
+CREATE TABLE test ();
+PREPARE prep1 AS SELECT COUNT(*) FROM test;;
+EXECUTE prep1;
+EXECUTE prep1;
+EXECUTE prep1;
+ALTER TABLE test ADD COLUMN x int;
+EXECUTE prep1;
+SELECT 42;
+SELECT 42;
+SELECT 42;
+SELECT query, plans, calls, rows FROM pg_stat_statements ORDER BY query COLLATE "C";
+
 DROP EXTENSION pg_stat_statements;
diff --git a/doc/src/sgml/pgstatstatements.sgml b/doc/src/sgml/pgstatstatements.sgml
index 26bb82da4a..368daf3e39 100644
--- a/doc/src/sgml/pgstatstatements.sgml
+++ b/doc/src/sgml/pgstatstatements.sgml
@@ -9,7 +9,8 @@
 
  <para>
   The <filename>pg_stat_statements</filename> module provides a means for
-  tracking execution statistics of all SQL statements executed by a server.
+  tracking planning and execution statistics of all SQL statements executed by
+  a server.
  </para>
 
  <para>
@@ -82,6 +83,20 @@
       <entry>Text of a representative statement</entry>
      </row>
 
+     <row>
+      <entry><structfield>plans</structfield></entry>
+      <entry><type>bigint</type></entry>
+      <entry></entry>
+      <entry>Number of times the statement was planned</entry>
+     </row>
+
+     <row>
+      <entry><structfield>total_plan_time</structfield></entry>
+      <entry><type>double precision</type></entry>
+      <entry></entry>
+      <entry>Total time spent planning the statement, in milliseconds</entry>
+     </row>
+
      <row>
       <entry><structfield>calls</structfield></entry>
       <entry><type>bigint</type></entry>
@@ -89,39 +104,46 @@
       <entry>Number of times executed</entry>
      </row>
 
+     <row>
+      <entry><structfield>total_exec_time</structfield></entry>
+      <entry><type>double precision</type></entry>
+      <entry></entry>
+      <entry>Total time spent executing the statement, in milliseconds</entry>
+     </row>
+
      <row>
       <entry><structfield>total_time</structfield></entry>
       <entry><type>double precision</type></entry>
       <entry></entry>
-      <entry>Total time spent in the statement, in milliseconds</entry>
+      <entry>Total time spent planning and executing the statement, in milliseconds</entry>
      </row>
 
      <row>
       <entry><structfield>min_time</structfield></entry>
       <entry><type>double precision</type></entry>
       <entry></entry>
-      <entry>Minimum time spent in the statement, in milliseconds</entry>
+      <entry>Minimum time spent executing the statement, in milliseconds</entry>
      </row>
 
      <row>
       <entry><structfield>max_time</structfield></entry>
       <entry><type>double precision</type></entry>
       <entry></entry>
-      <entry>Maximum time spent in the statement, in milliseconds</entry>
+      <entry>Maximum time spent executing the statement, in milliseconds</entry>
      </row>
 
      <row>
       <entry><structfield>mean_time</structfield></entry>
       <entry><type>double precision</type></entry>
       <entry></entry>
-      <entry>Mean time spent in the statement, in milliseconds</entry>
+      <entry>Mean time spent executing the statement, in milliseconds</entry>
      </row>
 
      <row>
       <entry><structfield>stddev_time</structfield></entry>
       <entry><type>double precision</type></entry>
       <entry></entry>
-      <entry>Population standard deviation of time spent in the statement, in milliseconds</entry>
+      <entry>Population standard deviation of time spent executing the statement, in milliseconds</entry>
      </row>
 
      <row>
@@ -431,6 +453,21 @@
     </listitem>
    </varlistentry>
 
+   <varlistentry>
+    <term>
+     <varname>pg_stat_statements.track_planning</varname> (<type>boolean</type>)
+    </term>
+
+    <listitem>
+     <para>
+      <varname>pg_stat_statements.track_planning</varname> controls whether
+      planning operations and duration are tracked by the module.
+      The default value is <literal>on</literal>.
+      Only superusers can change this setting.
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry>
     <term>
      <varname>pg_stat_statements.track_utility</varname> (<type>boolean</type>)
-- 
2.22.0

