Hi, Anton! I've corrected the patch and attached a new version.
-- Andrei Zubkov Postgres Professional: http://www.postgrespro.com The Russian Postgres Company On Wed, 2021-10-06 at 18:13 +0300, Мельников Антон Андреевич wrote: > Hi, Andrey! > > I’ve tried to apply your patch v2-0001 on current master, but i > failed. > There were git apply errors at: > pg_stat_statements.out:941 > pg_stat_statements.sql:385 > > Best Regards, > > Anton Melnikov > Postgres Professional: http://www.postgrespro.com > The Russian Postgres Company >
From e44b634f21216791c9b5fd9a533532437039dcc1 Mon Sep 17 00:00:00 2001 From: Andrei Zubkov <zub...@moonset.ru> Date: Thu, 7 Oct 2021 13:07:36 +0300 Subject: [PATCH] pg_stat_statements: Track statement entry timestamp Added first_seen column in pg_stat_statements view. This field is populated with current timestamp when a new statement is added to pg_stat_statements hashtable. This field provides clean information about statistics collection time interval for each statement. Besides it can be used by sampling solutions to detect situations when a statement was evicted and returned back between two samples. Discussion: https://www.postgresql.org/message-id/flat/72e80e7b160a6eb189df9ef6f068cce3765d37f8.camel%40moonset.ru --- contrib/pg_stat_statements/Makefile | 3 +- .../expected/pg_stat_statements.out | 29 +++++++++ .../pg_stat_statements--1.9--1.10.sql | 59 +++++++++++++++++++ .../pg_stat_statements/pg_stat_statements.c | 31 +++++++++- .../pg_stat_statements.control | 2 +- .../sql/pg_stat_statements.sql | 9 +++ doc/src/sgml/pgstatstatements.sgml | 9 +++ 7 files changed, 137 insertions(+), 5 deletions(-) create mode 100644 contrib/pg_stat_statements/pg_stat_statements--1.9--1.10.sql diff --git a/contrib/pg_stat_statements/Makefile b/contrib/pg_stat_statements/Makefile index 7fabd96f38..edc40c8bbf 100644 --- a/contrib/pg_stat_statements/Makefile +++ b/contrib/pg_stat_statements/Makefile @@ -6,7 +6,8 @@ OBJS = \ pg_stat_statements.o EXTENSION = pg_stat_statements -DATA = pg_stat_statements--1.4.sql pg_stat_statements--1.8--1.9.sql \ +DATA = pg_stat_statements--1.4.sql \ + pg_stat_statements--1.9--1.10.sql pg_stat_statements--1.8--1.9.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 \ diff --git a/contrib/pg_stat_statements/expected/pg_stat_statements.out b/contrib/pg_stat_statements/expected/pg_stat_statements.out index b52d187722..c5b5d8082f 100644 --- a/contrib/pg_stat_statements/expected/pg_stat_statements.out +++ b/contrib/pg_stat_statements/expected/pg_stat_statements.out @@ -1077,4 +1077,33 @@ SELECT COUNT(*) FROM pg_stat_statements WHERE query LIKE '%SELECT GROUPING%'; 2 (1 row) +-- +-- statement timestamps +-- +SELECT pg_stat_statements_reset(); + pg_stat_statements_reset +-------------------------- + +(1 row) + +SELECT 1 AS "STMTTS1"; + STMTTS1 +--------- + 1 +(1 row) + +SELECT now() AS ref_ts \gset +SELECT 1,2 AS "STMTTS2"; + ?column? | STMTTS2 +----------+--------- + 1 | 2 +(1 row) + +SELECT first_seen >= :'ref_ts', count(*) FROM pg_stat_statements WHERE query LIKE '%STMTTS%' GROUP BY first_seen >= :'ref_ts' ORDER BY first_seen >= :'ref_ts'; + ?column? | count +----------+------- + f | 1 + t | 1 +(2 rows) + DROP EXTENSION pg_stat_statements; diff --git a/contrib/pg_stat_statements/pg_stat_statements--1.9--1.10.sql b/contrib/pg_stat_statements/pg_stat_statements--1.9--1.10.sql new file mode 100644 index 0000000000..969a30fbdc --- /dev/null +++ b/contrib/pg_stat_statements/pg_stat_statements--1.9--1.10.sql @@ -0,0 +1,59 @@ +/* contrib/pg_stat_statements/pg_stat_statements--1.9--1.10.sql */ + +-- complain if script is sourced in psql, rather than via ALTER EXTENSION +\echo Use "ALTER EXTENSION pg_stat_statements UPDATE TO '1.10'" to load this file. \quit + +/* We need to redefine a view and a function */ +/* 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 toplevel bool, + OUT queryid bigint, + OUT query text, + OUT plans int8, + OUT total_plan_time float8, + OUT min_plan_time float8, + OUT max_plan_time float8, + OUT mean_plan_time float8, + OUT stddev_plan_time float8, + OUT calls int8, + OUT total_exec_time float8, + OUT min_exec_time float8, + OUT max_exec_time float8, + OUT mean_exec_time float8, + OUT stddev_exec_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 wal_records int8, + OUT wal_fpi int8, + OUT wal_bytes numeric, + OUT first_seen timestamp with time zone +) +RETURNS SETOF record +AS 'MODULE_PATHNAME', 'pg_stat_statements_1_10' +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; diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c index 07fe0e7cda..88cadd435f 100644 --- a/contrib/pg_stat_statements/pg_stat_statements.c +++ b/contrib/pg_stat_statements/pg_stat_statements.c @@ -88,7 +88,7 @@ PG_MODULE_MAGIC; #define PGSS_TEXT_FILE PG_STAT_TMP_DIR "/pgss_query_texts.stat" /* Magic number identifying the stats file format */ -static const uint32 PGSS_FILE_HEADER = 0x20201227; +static const uint32 PGSS_FILE_HEADER = 0x20210322; /* PostgreSQL major version number, changes in which invalidate all entries */ static const uint32 PGSS_PG_MAJOR_VERSION = PG_VERSION_NUM / 100; @@ -121,7 +121,8 @@ typedef enum pgssVersion PGSS_V1_2, PGSS_V1_3, PGSS_V1_8, - PGSS_V1_9 + PGSS_V1_9, + PGSS_V1_10 } pgssVersion; typedef enum pgssStoreKind @@ -214,6 +215,7 @@ typedef struct pgssEntry Size query_offset; /* query text offset in external file */ int query_len; /* # of valid bytes in query string, or -1 */ int encoding; /* query text encoding */ + TimestampTz first_seen; /* timestamp of entry allocation moment */ slock_t mutex; /* protects the counters only */ } pgssEntry; @@ -302,6 +304,7 @@ 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_1_9); +PG_FUNCTION_INFO_V1(pg_stat_statements_1_10); PG_FUNCTION_INFO_V1(pg_stat_statements); PG_FUNCTION_INFO_V1(pg_stat_statements_info); @@ -649,6 +652,7 @@ pgss_shmem_startup(void) /* copy in the actual stats */ entry->counters = temp.counters; + entry->first_seen = temp.first_seen; } /* Read global statistics for pg_stat_statements */ @@ -1426,7 +1430,8 @@ pg_stat_statements_reset(PG_FUNCTION_ARGS) #define PG_STAT_STATEMENTS_COLS_V1_3 23 #define PG_STAT_STATEMENTS_COLS_V1_8 32 #define PG_STAT_STATEMENTS_COLS_V1_9 33 -#define PG_STAT_STATEMENTS_COLS 33 /* maximum of above */ +#define PG_STAT_STATEMENTS_COLS_V1_10 34 +#define PG_STAT_STATEMENTS_COLS 34 /* maximum of above */ /* * Retrieve statement statistics. @@ -1438,6 +1443,16 @@ 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_10(PG_FUNCTION_ARGS) +{ + bool showtext = PG_GETARG_BOOL(0); + + pg_stat_statements_internal(fcinfo, PGSS_V1_10, showtext); + + return (Datum) 0; +} + Datum pg_stat_statements_1_9(PG_FUNCTION_ARGS) { @@ -1571,6 +1586,10 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo, if (api_version != PGSS_V1_9) elog(ERROR, "incorrect number of output arguments"); break; + case PG_STAT_STATEMENTS_COLS_V1_10: + if (api_version != PGSS_V1_10) + elog(ERROR, "incorrect number of output arguments"); + break; default: elog(ERROR, "incorrect number of output arguments"); } @@ -1656,6 +1675,7 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo, Counters tmp; double stddev; int64 queryid = entry->key.queryid; + TimestampTz first_seen; memset(values, 0, sizeof(values)); memset(nulls, 0, sizeof(nulls)); @@ -1724,6 +1744,7 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo, SpinLockAcquire(&e->mutex); tmp = e->counters; + first_seen = e->first_seen; SpinLockRelease(&e->mutex); } @@ -1795,6 +1816,8 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo, Int32GetDatum(-1)); values[i++] = wal_bytes; } + if (api_version >= PGSS_V1_10) + values[i++] = TimestampTzGetDatum(first_seen); Assert(i == (api_version == PGSS_V1_0 ? PG_STAT_STATEMENTS_COLS_V1_0 : api_version == PGSS_V1_1 ? PG_STAT_STATEMENTS_COLS_V1_1 : @@ -1802,6 +1825,7 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo, api_version == PGSS_V1_3 ? PG_STAT_STATEMENTS_COLS_V1_3 : api_version == PGSS_V1_8 ? PG_STAT_STATEMENTS_COLS_V1_8 : api_version == PGSS_V1_9 ? PG_STAT_STATEMENTS_COLS_V1_9 : + api_version == PGSS_V1_10 ? PG_STAT_STATEMENTS_COLS_V1_10 : -1 /* fail if you forget to update this assert */ )); tuplestore_putvalues(tupstore, tupdesc, values, nulls); @@ -1917,6 +1941,7 @@ entry_alloc(pgssHashKey *key, Size query_offset, int query_len, int encoding, entry->query_offset = query_offset; entry->query_len = query_len; entry->encoding = encoding; + entry->first_seen = GetCurrentTimestamp(); } return entry; diff --git a/contrib/pg_stat_statements/pg_stat_statements.control b/contrib/pg_stat_statements/pg_stat_statements.control index 2f1ce6ed50..0747e48138 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 planning and execution statistics of all SQL statements executed' -default_version = '1.9' +default_version = '1.10' 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 dffd2c8c18..44a766c9a8 100644 --- a/contrib/pg_stat_statements/sql/pg_stat_statements.sql +++ b/contrib/pg_stat_statements/sql/pg_stat_statements.sql @@ -442,4 +442,13 @@ SELECT ( SELECT COUNT(*) FROM pg_stat_statements WHERE query LIKE '%SELECT GROUPING%'; +-- +-- statement timestamps +-- +SELECT pg_stat_statements_reset(); +SELECT 1 AS "STMTTS1"; +SELECT now() AS ref_ts \gset +SELECT 1,2 AS "STMTTS2"; +SELECT first_seen >= :'ref_ts', count(*) FROM pg_stat_statements WHERE query LIKE '%STMTTS%' GROUP BY first_seen >= :'ref_ts' ORDER BY first_seen >= :'ref_ts'; + DROP EXTENSION pg_stat_statements; diff --git a/doc/src/sgml/pgstatstatements.sgml b/doc/src/sgml/pgstatstatements.sgml index 70b28a92c1..6484fb6298 100644 --- a/doc/src/sgml/pgstatstatements.sgml +++ b/doc/src/sgml/pgstatstatements.sgml @@ -379,6 +379,15 @@ Total amount of WAL generated by the statement in bytes </para></entry> </row> + + <row> + <entry role="catalog_table_entry"><para role="column_definition"> + <structfield>first_seen</structfield> <type>timestamp with time zone</type> + </para> + <para> + Timestamp of statistics gathering start for the statement + </para></entry> + </row> </tbody> </tgroup> </table> -- 2.30.2
