[PROPOSAL] timestamp informations to pg_stat_statements

From 6d8f2d39af797e079bc5e8f8323d4081e4742d5e Mon Sep 17 00:00:00 2001
From: Jason Kim <dialogbox@gmail.com>
Date: Sun, 17 Jul 2016 15:14:39 +0900
Subject: [PATCH] I added columns to track timestamp of first executed and last
 execute. There are many use case of these informations. Without these, we
 have to reset whole stats to gather similar infomations.

---
 contrib/pg_stat_statements/Makefile                |  7 +--
 .../pg_stat_statements--1.4--1.5.sql               | 58 ++++++++++++++++++++++
 .../pg_stat_statements/pg_stat_statements--1.4.sql | 48 ------------------
 .../pg_stat_statements/pg_stat_statements--1.5.sql | 50 +++++++++++++++++++
 contrib/pg_stat_statements/pg_stat_statements.c    | 33 +++++++++++-
 .../pg_stat_statements/pg_stat_statements.control  |  2 +-
 6 files changed, 144 insertions(+), 54 deletions(-)
 create mode 100644 contrib/pg_stat_statements/pg_stat_statements--1.4--1.5.sql
 delete mode 100644 contrib/pg_stat_statements/pg_stat_statements--1.4.sql
 create mode 100644 contrib/pg_stat_statements/pg_stat_statements--1.5.sql

diff --git a/contrib/pg_stat_statements/Makefile b/contrib/pg_stat_statements/Makefile
index ddcdb10..20aafaa 100644
--- a/contrib/pg_stat_statements/Makefile
+++ b/contrib/pg_stat_statements/Makefile
@@ -4,9 +4,10 @@ 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--1.3--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 pg_stat_statements--unpackaged--1.0.sql
+DATA = pg_stat_statements--1.5.sql pg_stat_statements--1.3--1.4.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 \
+	pg_stat_statements--unpackaged--1.0.sql
 PGFILEDESC = "pg_stat_statements - execution statistics of SQL statements"
 
 LDFLAGS_SL += $(filter -lm, $(LIBS))
diff --git a/contrib/pg_stat_statements/pg_stat_statements--1.4--1.5.sql b/contrib/pg_stat_statements/pg_stat_statements--1.4--1.5.sql
new file mode 100644
index 0000000..c54a735
--- /dev/null
+++ b/contrib/pg_stat_statements/pg_stat_statements--1.4--1.5.sql
@@ -0,0 +1,58 @@
+/* contrib/pg_stat_statements/pg_stat_statements--1.4--1.5.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION pg_stat_statements UPDATE TO '1.5'" 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_reset()
+RETURNS void
+AS 'MODULE_PATHNAME'
+LANGUAGE C PARALLEL SAFE;
+
+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,
+    OUT created timestamp with time zone,
+    OUT last_updated timestamp with time zone
+)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'pg_stat_statements_1_5'
+LANGUAGE C STRICT VOLATILE PARALLEL SAFE;
+
+-- Register a view on the function for ease of use.
+CREATE VIEW pg_stat_statements AS
+  SELECT * FROM pg_stat_statements(true);
+
+GRANT SELECT ON pg_stat_statements TO PUBLIC;
+
+-- Don't want this to be available to non-superusers.
+REVOKE ALL ON FUNCTION pg_stat_statements_reset() FROM PUBLIC;
diff --git a/contrib/pg_stat_statements/pg_stat_statements--1.4.sql b/contrib/pg_stat_statements/pg_stat_statements--1.4.sql
deleted file mode 100644
index 58cdf60..0000000
--- a/contrib/pg_stat_statements/pg_stat_statements--1.4.sql
+++ /dev/null
@@ -1,48 +0,0 @@
-/* contrib/pg_stat_statements/pg_stat_statements--1.4.sql */
-
--- complain if script is sourced in psql, rather than via CREATE EXTENSION
-\echo Use "CREATE EXTENSION pg_stat_statements" to load this file. \quit
-
--- Register functions.
-CREATE FUNCTION pg_stat_statements_reset()
-RETURNS void
-AS 'MODULE_PATHNAME'
-LANGUAGE C PARALLEL SAFE;
-
-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_3'
-LANGUAGE C STRICT VOLATILE PARALLEL SAFE;
-
--- Register a view on the function for ease of use.
-CREATE VIEW pg_stat_statements AS
-  SELECT * FROM pg_stat_statements(true);
-
-GRANT SELECT ON pg_stat_statements TO PUBLIC;
-
--- Don't want this to be available to non-superusers.
-REVOKE ALL ON FUNCTION pg_stat_statements_reset() FROM PUBLIC;
diff --git a/contrib/pg_stat_statements/pg_stat_statements--1.5.sql b/contrib/pg_stat_statements/pg_stat_statements--1.5.sql
new file mode 100644
index 0000000..957706a
--- /dev/null
+++ b/contrib/pg_stat_statements/pg_stat_statements--1.5.sql
@@ -0,0 +1,50 @@
+/* contrib/pg_stat_statements/pg_stat_statements--1.5.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION pg_stat_statements" to load this file. \quit
+
+-- Register functions.
+CREATE FUNCTION pg_stat_statements_reset()
+RETURNS void
+AS 'MODULE_PATHNAME'
+LANGUAGE C PARALLEL SAFE;
+
+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,
+    OUT created timestamp with time zone,
+    OUT last_updated timestamp with time zone
+)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'pg_stat_statements_1_5'
+LANGUAGE C STRICT VOLATILE PARALLEL SAFE;
+
+-- Register a view on the function for ease of use.
+CREATE VIEW pg_stat_statements AS
+  SELECT * FROM pg_stat_statements(true);
+
+GRANT SELECT ON pg_stat_statements TO PUBLIC;
+
+-- Don't want this to be available to non-superusers.
+REVOKE ALL ON FUNCTION pg_stat_statements_reset() FROM PUBLIC;
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
index 3d9b8e4..a6a017b 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -76,6 +76,7 @@
 #include "tcop/utility.h"
 #include "utils/builtins.h"
 #include "utils/memutils.h"
+#include "utils/timestamp.h"
 
 PG_MODULE_MAGIC;
 
@@ -117,7 +118,8 @@ typedef enum pgssVersion
 	PGSS_V1_0 = 0,
 	PGSS_V1_1,
 	PGSS_V1_2,
-	PGSS_V1_3
+	PGSS_V1_3,
+	PGSS_V1_5
 } pgssVersion;
 
 /*
@@ -156,6 +158,8 @@ typedef struct Counters
 	double		blk_read_time;	/* time spent reading, in msec */
 	double		blk_write_time; /* time spent writing, in msec */
 	double		usage;			/* usage factor */
+	TimestampTz		created;	/* timestamp of created time */
+	TimestampTz		last_updated;	/* timestamp of last updated */
 } Counters;
 
 /*
@@ -281,6 +285,7 @@ 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_5);
 PG_FUNCTION_INFO_V1(pg_stat_statements);
 
 static void pgss_shmem_startup(void);
@@ -1251,6 +1256,7 @@ pgss_store(const char *query, uint32 queryId,
 		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);
+		e->counters.last_updated = GetCurrentTimestamp();
 
 		SpinLockRelease(&e->mutex);
 	}
@@ -1282,7 +1288,8 @@ 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_5	25
+#define PG_STAT_STATEMENTS_COLS			25		/* maximum of above */
 
 /*
  * Retrieve statement statistics.
@@ -1295,6 +1302,16 @@ 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_5(PG_FUNCTION_ARGS)
+{
+	bool		showtext = PG_GETARG_BOOL(0);
+
+	pg_stat_statements_internal(fcinfo, PGSS_V1_5, showtext);
+
+	return (Datum) 0;
+}
+
+Datum
 pg_stat_statements_1_3(PG_FUNCTION_ARGS)
 {
 	bool		showtext = PG_GETARG_BOOL(0);
@@ -1397,6 +1414,10 @@ 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_5:
+			if (api_version != PGSS_V1_5)
+				elog(ERROR, "incorrect number of output arguments");
+			break;
 		default:
 			elog(ERROR, "incorrect number of output arguments");
 	}
@@ -1593,11 +1614,17 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 			values[i++] = Float8GetDatumFast(tmp.blk_read_time);
 			values[i++] = Float8GetDatumFast(tmp.blk_write_time);
 		}
+		if (api_version >= PGSS_V1_5)
+		{
+			values[i++] = Int64GetDatumFast(tmp.created);
+			values[i++] = Int64GetDatumFast(tmp.last_updated);
+		}
 
 		Assert(i == (api_version == PGSS_V1_0 ? PG_STAT_STATEMENTS_COLS_V1_0 :
 					 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_5 ? PG_STAT_STATEMENTS_COLS_V1_5 :
 					 -1 /* fail if you forget to update this assert */ ));
 
 		tuplestore_putvalues(tupstore, tupdesc, values, nulls);
@@ -1663,6 +1690,8 @@ entry_alloc(pgssHashKey *key, Size query_offset, int query_len, int encoding,
 
 		/* reset the statistics */
 		memset(&entry->counters, 0, sizeof(Counters));
+		/* set the created timestamp */
+    entry->counters.created = GetCurrentTimestamp();
 		/* set the appropriate initial usage count */
 		entry->counters.usage = sticky ? pgss->cur_median_usage : USAGE_INIT;
 		/* re-initialize the mutex each time ... we assume no one using it */
diff --git a/contrib/pg_stat_statements/pg_stat_statements.control b/contrib/pg_stat_statements/pg_stat_statements.control
index 24038f5..193fcdf 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 = '1.4'
+default_version = '1.5'
 module_pathname = '$libdir/pg_stat_statements'
 relocatable = true
-- 
2.7.4 (Apple Git-66)