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Track statement entry timestamp in contrib/pg_stat_statements
This patch adds 'stats_since' and 'minmax_stats_since' columns to the pg_stat_statements view and pg_stat_statements() function. The new min/max reset mode for the pg_stat_stetments_reset() function is controlled by the parameter minmax_only. 'stat_since' column is populated with the current timestamp when a new statement is added to the pg_stat_statements hashtable. It provides clean information about statistics collection time intervals for each statement. Besides it can be used by sampling solutions to detect situations when a statement was evicted and stored again between samples. Such a sampling solution could derive any pg_stat_statements statistic values for an interval between two samples with the exception of all min/max statistics. To address this issue this patch adds the ability to reset min/max statistics independently of the statement reset using the new minmax_only parameter of the pg_stat_statements_reset(userid oid, dbid oid, queryid bigint, minmax_only boolean) function. The timestamp of such reset is stored in the minmax_stats_since field for each statement. pg_stat_statements_reset() function now returns the timestamp of a reset as the result. Discussion: https://postgr.es/m/flat/72e80e7b160a6eb189df9ef6f068cce3765d37f8.camel%40moonset.ru Author: Andrei Zubkov Reviewed-by: Julien Rouhaud, Hayato Kuroda, Yuki Seino, Chengxi Sun Reviewed-by: Anton Melnikov, Darren Rush, Michael Paquier, Sergei Kornilov Reviewed-by: Alena Rybakina, Andrei Lepikhov
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‎contrib/pg_stat_statements/Makefile‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -19,7 +19,7 @@ LDFLAGS_SL += $(filter -lm, $(LIBS))
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2020
REGRESS_OPTS = --temp-config $(top_srcdir)/contrib/pg_stat_statements/pg_stat_statements.conf
2121
REGRESS = select dml cursors utility level_tracking planning \
22-
user_activity wal cleanup oldextversions
22+
user_activity wal entry_timestamp cleanup oldextversions
2323
# Disabled because these tests require "shared_preload_libraries=pg_stat_statements",
2424
# which typical installcheck users do not have (e.g. buildfarm clients).
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NO_INSTALLCHECK = 1

‎contrib/pg_stat_statements/expected/entry_timestamp.out‎

Lines changed: 159 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,159 @@
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--
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-- statement timestamps
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--
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-- planning time is needed during tests
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SET pg_stat_statements.track_planning = TRUE;
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SELECT 1 AS "STMTTS1";
7+
STMTTS1
8+
---------
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1
10+
(1 row)
11+
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SELECT now() AS ref_ts \gset
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SELECT 1,2 AS "STMTTS2";
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?column? | STMTTS2
15+
----------+---------
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1 | 2
17+
(1 row)
18+
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SELECT stats_since >= :'ref_ts', count(*) FROM pg_stat_statements
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WHERE query LIKE '%STMTTS%'
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GROUP BY stats_since >= :'ref_ts'
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ORDER BY stats_since >= :'ref_ts';
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?column? | count
24+
----------+-------
25+
f | 1
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t | 1
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(2 rows)
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SELECT now() AS ref_ts \gset
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SELECT
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count(*) as total,
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count(*) FILTER (
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WHERE min_plan_time + max_plan_time = 0
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) as minmax_plan_zero,
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count(*) FILTER (
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WHERE min_exec_time + max_exec_time = 0
37+
) as minmax_exec_zero,
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count(*) FILTER (
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WHERE minmax_stats_since >= :'ref_ts'
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) as minmax_stats_since_after_ref,
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count(*) FILTER (
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WHERE stats_since >= :'ref_ts'
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) as stats_since_after_ref
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FROM pg_stat_statements
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WHERE query LIKE '%STMTTS%';
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total | minmax_plan_zero | minmax_exec_zero | minmax_stats_since_after_ref | stats_since_after_ref
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-------+------------------+------------------+------------------------------+-----------------------
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2 | 0 | 0 | 0 | 0
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(1 row)
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-- Perform single min/max reset
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SELECT pg_stat_statements_reset(0, 0, queryid, true) AS minmax_reset_ts
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FROM pg_stat_statements
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WHERE query LIKE '%STMTTS1%' \gset
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-- check
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SELECT
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count(*) as total,
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count(*) FILTER (
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WHERE min_plan_time + max_plan_time = 0
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) as minmax_plan_zero,
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count(*) FILTER (
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WHERE min_exec_time + max_exec_time = 0
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) as minmax_exec_zero,
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count(*) FILTER (
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WHERE minmax_stats_since >= :'ref_ts'
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) as minmax_stats_since_after_ref,
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count(*) FILTER (
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WHERE stats_since >= :'ref_ts'
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) as stats_since_after_ref
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FROM pg_stat_statements
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WHERE query LIKE '%STMTTS%';
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total | minmax_plan_zero | minmax_exec_zero | minmax_stats_since_after_ref | stats_since_after_ref
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-------+------------------+------------------+------------------------------+-----------------------
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2 | 1 | 1 | 1 | 0
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(1 row)
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-- check minmax reset timestamps
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SELECT
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query, minmax_stats_since = :'minmax_reset_ts' AS reset_ts_match
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FROM pg_stat_statements
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WHERE query LIKE '%STMTTS%'
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ORDER BY query COLLATE "C";
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query | reset_ts_match
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---------------------------+----------------
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SELECT $1 AS "STMTTS1" | t
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SELECT $1,$2 AS "STMTTS2" | f
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(2 rows)
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-- check that minmax reset does not set stats_reset
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SELECT
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stats_reset = :'minmax_reset_ts' AS stats_reset_ts_match
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FROM pg_stat_statements_info;
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stats_reset_ts_match
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----------------------
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f
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(1 row)
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-- Perform common min/max reset
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SELECT pg_stat_statements_reset(0, 0, 0, true) AS minmax_reset_ts \gset
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-- check again
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SELECT
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count(*) as total,
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count(*) FILTER (
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WHERE min_plan_time + max_plan_time = 0
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) as minmax_plan_zero,
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count(*) FILTER (
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WHERE min_exec_time + max_exec_time = 0
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) as minmax_exec_zero,
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count(*) FILTER (
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WHERE minmax_stats_since >= :'ref_ts'
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) as minmax_ts_after_ref,
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count(*) FILTER (
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WHERE minmax_stats_since = :'minmax_reset_ts'
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) as minmax_ts_match,
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count(*) FILTER (
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WHERE stats_since >= :'ref_ts'
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) as stats_since_after_ref
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FROM pg_stat_statements
119+
WHERE query LIKE '%STMTTS%';
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total | minmax_plan_zero | minmax_exec_zero | minmax_ts_after_ref | minmax_ts_match | stats_since_after_ref
121+
-------+------------------+------------------+---------------------+-----------------+-----------------------
122+
2 | 2 | 2 | 2 | 2 | 0
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(1 row)
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125+
-- Execute first query once more to check stats update
126+
SELECT 1 AS "STMTTS1";
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STMTTS1
128+
---------
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1
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(1 row)
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-- check
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-- we don't check planing times here to be independent of
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-- plan caching approach
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SELECT
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count(*) as total,
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count(*) FILTER (
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WHERE min_exec_time + max_exec_time = 0
139+
) as minmax_exec_zero,
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count(*) FILTER (
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WHERE minmax_stats_since >= :'ref_ts'
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) as minmax_ts_after_ref,
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count(*) FILTER (
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WHERE stats_since >= :'ref_ts'
145+
) as stats_since_after_ref
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FROM pg_stat_statements
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WHERE query LIKE '%STMTTS%';
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total | minmax_exec_zero | minmax_ts_after_ref | stats_since_after_ref
149+
-------+------------------+---------------------+-----------------------
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2 | 1 | 2 | 0
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(1 row)
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-- Cleanup
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SELECT pg_stat_statements_reset() IS NOT NULL AS t;
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t
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---
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t
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(1 row)
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‎contrib/pg_stat_statements/expected/oldextversions.out‎

Lines changed: 65 additions & 51 deletions
Original file line numberDiff line numberDiff line change
@@ -250,64 +250,78 @@ SELECT count(*) > 0 AS has_data FROM pg_stat_statements;
250250
t
251251
(1 row)
252252

253-
-- New views for pg_stat_statements in 1.11
253+
-- New functions and views for pg_stat_statements in 1.11
254254
AlTER EXTENSION pg_stat_statements UPDATE TO '1.11';
255255
\d pg_stat_statements
256-
View "public.pg_stat_statements"
257-
Column | Type | Collation | Nullable | Default
258-
------------------------+------------------+-----------+----------+---------
259-
userid | oid | | |
260-
dbid | oid | | |
261-
toplevel | boolean | | |
262-
queryid | bigint | | |
263-
query | text | | |
264-
plans | bigint | | |
265-
total_plan_time | double precision | | |
266-
min_plan_time | double precision | | |
267-
max_plan_time | double precision | | |
268-
mean_plan_time | double precision | | |
269-
stddev_plan_time | double precision | | |
270-
calls | bigint | | |
271-
total_exec_time | double precision | | |
272-
min_exec_time | double precision | | |
273-
max_exec_time | double precision | | |
274-
mean_exec_time | double precision | | |
275-
stddev_exec_time | double precision | | |
276-
rows | bigint | | |
277-
shared_blks_hit | bigint | | |
278-
shared_blks_read | bigint | | |
279-
shared_blks_dirtied | bigint | | |
280-
shared_blks_written | bigint | | |
281-
local_blks_hit | bigint | | |
282-
local_blks_read | bigint | | |
283-
local_blks_dirtied | bigint | | |
284-
local_blks_written | bigint | | |
285-
temp_blks_read | bigint | | |
286-
temp_blks_written | bigint | | |
287-
shared_blk_read_time | double precision | | |
288-
shared_blk_write_time | double precision | | |
289-
local_blk_read_time | double precision | | |
290-
local_blk_write_time | double precision | | |
291-
temp_blk_read_time | double precision | | |
292-
temp_blk_write_time | double precision | | |
293-
wal_records | bigint | | |
294-
wal_fpi | bigint | | |
295-
wal_bytes | numeric | | |
296-
jit_functions | bigint | | |
297-
jit_generation_time | double precision | | |
298-
jit_inlining_count | bigint | | |
299-
jit_inlining_time | double precision | | |
300-
jit_optimization_count | bigint | | |
301-
jit_optimization_time | double precision | | |
302-
jit_emission_count | bigint | | |
303-
jit_emission_time | double precision | | |
304-
jit_deform_count | bigint | | |
305-
jit_deform_time | double precision | | |
256+
View "public.pg_stat_statements"
257+
Column | Type | Collation | Nullable | Default
258+
------------------------+--------------------------+-----------+----------+---------
259+
userid | oid | | |
260+
dbid | oid | | |
261+
toplevel | boolean | | |
262+
queryid | bigint | | |
263+
query | text | | |
264+
plans | bigint | | |
265+
total_plan_time | double precision | | |
266+
min_plan_time | double precision | | |
267+
max_plan_time | double precision | | |
268+
mean_plan_time | double precision | | |
269+
stddev_plan_time | double precision | | |
270+
calls | bigint | | |
271+
total_exec_time | double precision | | |
272+
min_exec_time | double precision | | |
273+
max_exec_time | double precision | | |
274+
mean_exec_time | double precision | | |
275+
stddev_exec_time | double precision | | |
276+
rows | bigint | | |
277+
shared_blks_hit | bigint | | |
278+
shared_blks_read | bigint | | |
279+
shared_blks_dirtied | bigint | | |
280+
shared_blks_written | bigint | | |
281+
local_blks_hit | bigint | | |
282+
local_blks_read | bigint | | |
283+
local_blks_dirtied | bigint | | |
284+
local_blks_written | bigint | | |
285+
temp_blks_read | bigint | | |
286+
temp_blks_written | bigint | | |
287+
shared_blk_read_time | double precision | | |
288+
shared_blk_write_time | double precision | | |
289+
local_blk_read_time | double precision | | |
290+
local_blk_write_time | double precision | | |
291+
temp_blk_read_time | double precision | | |
292+
temp_blk_write_time | double precision | | |
293+
wal_records | bigint | | |
294+
wal_fpi | bigint | | |
295+
wal_bytes | numeric | | |
296+
jit_functions | bigint | | |
297+
jit_generation_time | double precision | | |
298+
jit_inlining_count | bigint | | |
299+
jit_inlining_time | double precision | | |
300+
jit_optimization_count | bigint | | |
301+
jit_optimization_time | double precision | | |
302+
jit_emission_count | bigint | | |
303+
jit_emission_time | double precision | | |
304+
jit_deform_count | bigint | | |
305+
jit_deform_time | double precision | | |
306+
stats_since | timestamp with time zone | | |
307+
minmax_stats_since | timestamp with time zone | | |
306308

307309
SELECT count(*) > 0 AS has_data FROM pg_stat_statements;
308310
has_data
309311
----------
310312
t
311313
(1 row)
312314

315+
-- New parameter minmax_only of pg_stat_statements_reset function
316+
SELECT pg_get_functiondef('pg_stat_statements_reset'::regproc);
317+
pg_get_functiondef
318+
-------------------------------------------------------------------------------------------------------------------------------------------------------------------
319+
CREATE OR REPLACE FUNCTION public.pg_stat_statements_reset(userid oid DEFAULT 0, dbid oid DEFAULT 0, queryid bigint DEFAULT 0, minmax_only boolean DEFAULT false)+
320+
RETURNS timestamp with time zone +
321+
LANGUAGE c +
322+
PARALLEL SAFE STRICT +
323+
AS '$libdir/pg_stat_statements', $function$pg_stat_statements_reset_1_11$function$ +
324+
325+
(1 row)
326+
313327
DROP EXTENSION pg_stat_statements;

‎contrib/pg_stat_statements/meson.build‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -49,6 +49,7 @@ tests += {
4949
'planning',
5050
'user_activity',
5151
'wal',
52+
'entry_timestamp',
5253
'cleanup',
5354
'oldextversions',
5455
],

‎contrib/pg_stat_statements/pg_stat_statements--1.10--1.11.sql‎

Lines changed: 17 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -3,13 +3,10 @@
33
-- complain if script is sourced in psql, rather than via ALTER EXTENSION
44
\echo Use "ALTER EXTENSION pg_stat_statements UPDATE TO '1.11'" to load this file. \quit
55

6-
/* First we have to remove them from the extension */
7-
ALTER EXTENSION pg_stat_statements DROP VIEW pg_stat_statements;
8-
ALTER EXTENSION pg_stat_statements DROP FUNCTION pg_stat_statements(boolean);
9-
10-
/* Then we can drop them */
6+
/* Drop old versions */
117
DROP VIEW pg_stat_statements;
128
DROP FUNCTION pg_stat_statements(boolean);
9+
DROP FUNCTION pg_stat_statements_reset(Oid, Oid, bigint);
1310

1411
/* Now redefine */
1512
CREATE FUNCTION pg_stat_statements(IN showtext boolean,
@@ -59,7 +56,9 @@ CREATE FUNCTION pg_stat_statements(IN showtext boolean,
5956
OUT jit_emission_count int8,
6057
OUT jit_emission_time float8,
6158
OUT jit_deform_count int8,
62-
OUT jit_deform_time float8
59+
OUT jit_deform_time float8,
60+
OUT stats_since timestamp with time zone,
61+
OUT minmax_stats_since timestamp with time zone
6362
)
6463
RETURNS SETOF record
6564
AS 'MODULE_PATHNAME', 'pg_stat_statements_1_11'
@@ -69,3 +68,15 @@ CREATE VIEW pg_stat_statements AS
6968
SELECT * FROM pg_stat_statements(true);
7069

7170
GRANT SELECT ON pg_stat_statements TO PUBLIC;
71+
72+
CREATE FUNCTION pg_stat_statements_reset(IN userid Oid DEFAULT 0,
73+
IN dbid Oid DEFAULT 0,
74+
IN queryid bigint DEFAULT 0,
75+
IN minmax_only boolean DEFAULT false
76+
)
77+
RETURNS timestamp with time zone
78+
AS 'MODULE_PATHNAME', 'pg_stat_statements_reset_1_11'
79+
LANGUAGE C STRICT PARALLEL SAFE;
80+
81+
-- Don't want this to be available to non-superusers.
82+
REVOKE ALL ON FUNCTION pg_stat_statements_reset(Oid, Oid, bigint, boolean) FROM PUBLIC;

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