agora inbox for [email protected]help / color / mirror / Atom feed
[PATCH v7 15/16] Trigger authors need not worry about parallelism 14+ messages / 3 participants [nested] [flat]
* [PATCH v7 15/16] Trigger authors need not worry about parallelism @ 2023-10-02 19:55 Karl O. Pinc <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Karl O. Pinc @ 2023-10-02 19:55 UTC (permalink / raw) The idea is that it's worth telling the trigger author who comes across PARALLEL declarations when creating trigger functions that they don't need to investigate further. Is this stating the obvious? Yes. But it's not obvious until you've read about PGs parallelism, and read _enough_ to know that there's only mention of queries and no mention of data modification statements. Knowing that something is missing from PG requires at least passing familiarity with _all_ of the documentation. Plus, this patch adds an index entry so the new verbage is easy to find for those who do investigate. Agreed, documenting everything PG does _not_ do is a terrible idea. The goal here is to help trigger authors limit what they need to research. --- doc/src/sgml/trigger.sgml | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/doc/src/sgml/trigger.sgml b/doc/src/sgml/trigger.sgml index 6e1f370b21..f6ec8d2a97 100644 --- a/doc/src/sgml/trigger.sgml +++ b/doc/src/sgml/trigger.sgml @@ -377,6 +377,17 @@ trigger. </para> + <indexterm> + <primary>parallel safety</primary> + <secondary>triggers</secondary> + </indexterm> + + <para> + Trigger authors need not concern themselves with parallel safety. + <link linkend="parallel-query">Parallel execution</link> + is supported only in queries, + </para> + <para> Each programming language that supports triggers has its own method for making the trigger input data available to the trigger function. -- 2.30.2 --MP_/VSGM3xNEmY7iJyL2wuWRCjV Content-Type: text/x-patch Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=v7-0016-Predicate-locks-are-held-per-cluster-not-per-data.patch ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v6 15/15] Trigger authors need not worry about parallelism @ 2023-10-02 19:55 Karl O. Pinc <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Karl O. Pinc @ 2023-10-02 19:55 UTC (permalink / raw) The idea is that it's worth telling the trigger author who comes across PARALLEL declarations when creating trigger functions that they don't need to investigate further. Is this stating the obvious? Yes. But it's not obvious until you've read about PGs parallelism, and read _enough_ to know that there's only mention of queries and no mention of data modification statements. Knowing that something is missing from PG requires at least passing familiarity with _all_ of the documentation. Plus, this patch adds an index entry so the new verbage is easy to find for those who do investigate. Agreed, documenting everything PG does _not_ do is a terrible idea. The goal here is to help trigger authors limit what they need to research. --- doc/src/sgml/trigger.sgml | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/doc/src/sgml/trigger.sgml b/doc/src/sgml/trigger.sgml index 6e1f370b21..f6ec8d2a97 100644 --- a/doc/src/sgml/trigger.sgml +++ b/doc/src/sgml/trigger.sgml @@ -377,6 +377,17 @@ trigger. </para> + <indexterm> + <primary>parallel safety</primary> + <secondary>triggers</secondary> + </indexterm> + + <para> + Trigger authors need not concern themselves with parallel safety. + <link linkend="parallel-query">Parallel execution</link> + is supported only in queries, + </para> + <para> Each programming language that supports triggers has its own method for making the trigger input data available to the trigger function. -- 2.30.2 --MP_/74urtnrsBSymuH7bJczNOGS-- ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v15 4/8] Row pattern recognition patch (planner). @ 2024-03-28 10:30 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Tatsuo Ishii @ 2024-03-28 10:30 UTC (permalink / raw) --- src/backend/optimizer/plan/createplan.c | 24 +++++++++++++++----- src/backend/optimizer/plan/planner.c | 3 +++ src/backend/optimizer/plan/setrefs.c | 27 ++++++++++++++++++++++- src/backend/optimizer/prep/prepjointree.c | 4 ++++ src/include/nodes/plannodes.h | 19 ++++++++++++++++ 5 files changed, 71 insertions(+), 6 deletions(-) diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index 5f479fc56c..fe51ad351e 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -287,9 +287,11 @@ static WindowAgg *make_windowagg(List *tlist, Index winref, int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators, Oid *ordCollations, int frameOptions, Node *startOffset, Node *endOffset, Oid startInRangeFunc, Oid endInRangeFunc, - Oid inRangeColl, bool inRangeAsc, bool inRangeNullsFirst, - List *runCondition, List *qual, bool topWindow, - Plan *lefttree); + Oid inRangeColl, bool inRangeAsc, bool inRangeNullsFirst, List *runCondition, + RPSkipTo rpSkipTo, List *patternVariable, List *patternRegexp, + List *defineClause, + List *defineInitial, + List *qual, bool topWindow, Plan *lefttree); static Group *make_group(List *tlist, List *qual, int numGroupCols, AttrNumber *grpColIdx, Oid *grpOperators, Oid *grpCollations, Plan *lefttree); @@ -2699,6 +2701,11 @@ create_windowagg_plan(PlannerInfo *root, WindowAggPath *best_path) wc->inRangeAsc, wc->inRangeNullsFirst, wc->runCondition, + wc->rpSkipTo, + wc->patternVariable, + wc->patternRegexp, + wc->defineClause, + wc->defineInitial, best_path->qual, best_path->topwindow, subplan); @@ -6627,8 +6634,10 @@ make_windowagg(List *tlist, Index winref, int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators, Oid *ordCollations, int frameOptions, Node *startOffset, Node *endOffset, Oid startInRangeFunc, Oid endInRangeFunc, - Oid inRangeColl, bool inRangeAsc, bool inRangeNullsFirst, - List *runCondition, List *qual, bool topWindow, Plan *lefttree) + Oid inRangeColl, bool inRangeAsc, bool inRangeNullsFirst, List *runCondition, + RPSkipTo rpSkipTo, List *patternVariable, List *patternRegexp, List *defineClause, + List *defineInitial, + List *qual, bool topWindow, Plan *lefttree) { WindowAgg *node = makeNode(WindowAgg); Plan *plan = &node->plan; @@ -6654,6 +6663,11 @@ make_windowagg(List *tlist, Index winref, node->inRangeAsc = inRangeAsc; node->inRangeNullsFirst = inRangeNullsFirst; node->topWindow = topWindow; + node->rpSkipTo = rpSkipTo, + node->patternVariable = patternVariable; + node->patternRegexp = patternRegexp; + node->defineClause = defineClause; + node->defineInitial = defineInitial; plan->targetlist = tlist; plan->lefttree = lefttree; diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index 38d070fa00..82c370c4b4 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -869,6 +869,9 @@ subquery_planner(PlannerGlobal *glob, Query *parse, wc->runCondition = (List *) preprocess_expression(root, (Node *) wc->runCondition, EXPRKIND_TARGET); + wc->defineClause = (List *) preprocess_expression(root, + (Node *) wc->defineClause, + EXPRKIND_TARGET); } parse->limitOffset = preprocess_expression(root, parse->limitOffset, diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c index 42603dbc7c..f7abb2be96 100644 --- a/src/backend/optimizer/plan/setrefs.c +++ b/src/backend/optimizer/plan/setrefs.c @@ -210,7 +210,6 @@ static List *set_windowagg_runcondition_references(PlannerInfo *root, List *runcondition, Plan *plan); - /***************************************************************************** * * SUBPLAN REFERENCES @@ -2455,6 +2454,32 @@ set_upper_references(PlannerInfo *root, Plan *plan, int rtoffset) NRM_EQUAL, NUM_EXEC_QUAL(plan)); + /* + * Modifies an expression tree in each DEFINE clause so that all Var + * nodes's varno refers to OUTER_VAR. + */ + if (IsA(plan, WindowAgg)) + { + WindowAgg *wplan = (WindowAgg *) plan; + + if (wplan->defineClause != NIL) + { + foreach(l, wplan->defineClause) + { + TargetEntry *tle = (TargetEntry *) lfirst(l); + + tle->expr = (Expr *) + fix_upper_expr(root, + (Node *) tle->expr, + subplan_itlist, + OUTER_VAR, + rtoffset, + NRM_EQUAL, + NUM_EXEC_QUAL(plan)); + } + } + } + pfree(subplan_itlist); } diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c index 300691cc4d..3220072a51 100644 --- a/src/backend/optimizer/prep/prepjointree.c +++ b/src/backend/optimizer/prep/prepjointree.c @@ -2147,6 +2147,10 @@ perform_pullup_replace_vars(PlannerInfo *root, if (wc->runCondition != NIL) wc->runCondition = (List *) pullup_replace_vars((Node *) wc->runCondition, rvcontext); + + if (wc->defineClause != NIL) + wc->defineClause = (List *) + pullup_replace_vars((Node *) wc->defineClause, rvcontext); } if (parse->onConflict) { diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h index 7f3db5105d..b0e50ae886 100644 --- a/src/include/nodes/plannodes.h +++ b/src/include/nodes/plannodes.h @@ -20,6 +20,7 @@ #include "lib/stringinfo.h" #include "nodes/bitmapset.h" #include "nodes/lockoptions.h" +#include "nodes/parsenodes.h" #include "nodes/primnodes.h" @@ -1096,6 +1097,24 @@ typedef struct WindowAgg /* nulls sort first for in_range tests? */ bool inRangeNullsFirst; + /* Row Pattern Recognition AFTER MACH SKIP clause */ + RPSkipTo rpSkipTo; /* Row Pattern Skip To type */ + + /* Row Pattern PATTERN variable name (list of String) */ + List *patternVariable; + + /* + * Row Pattern RPATTERN regular expression quantifier ('+' or ''. list of + * String) + */ + List *patternRegexp; + + /* Row Pattern DEFINE clause (list of TargetEntry) */ + List *defineClause; + + /* Row Pattern DEFINE variable initial names (list of String) */ + List *defineInitial; + /* * false for all apart from the WindowAgg that's closest to the root of * the plan -- 2.25.1 ----Next_Part(Thu_Mar_28_19_59_25_2024_076)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v15-0005-Row-pattern-recognition-patch-executor.patch" ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v5 2/2] Add the pg_stat_lock view @ 2025-07-31 09:35 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Bertrand Drouvot @ 2025-07-31 09:35 UTC (permalink / raw) This new view reports lock statistics. Note that it does not omit combinations which do not make sense (as pg_locks does). Also wait_time is reported as bigint as the deadlock_timeout default value is 1s. This commit also adds documentation and a few tests. XXX: Bump catversion --- doc/src/sgml/monitoring.sgml | 113 +++++++++++++++++ src/backend/catalog/system_views.sql | 9 ++ src/backend/utils/activity/pgstat_lock.c | 8 ++ src/backend/utils/adt/pgstatfuncs.c | 39 ++++++ src/include/catalog/pg_proc.dat | 9 ++ src/include/pgstat.h | 1 + src/test/isolation/expected/stats.out | 147 +++++++++++++++++++++++ src/test/isolation/expected/stats_1.out | 147 +++++++++++++++++++++++ src/test/isolation/specs/stats.spec | 76 ++++++++++++ src/test/regress/expected/rules.out | 6 + src/test/regress/expected/stats.out | 42 +++++++ src/test/regress/sql/stats.sql | 30 +++++ 12 files changed, 627 insertions(+) 18.8% doc/src/sgml/ 5.9% src/backend/utils/adt/ 49.4% src/test/isolation/expected/ 11.3% src/test/isolation/specs/ 6.0% src/test/regress/expected/ 4.1% src/test/regress/sql/ 4.3% src/ diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index b77d189a500..3a196bc305c 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -493,6 +493,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser </entry> </row> + <row> + <entry><structname>pg_stat_lock</structname><indexterm><primary>pg_stat_lock</primary></indexterm></entry> + <entry> + One row for each lock type, containing cluster-wide locks statistics. + See <link linkend="monitoring-pg-stat-lock-view"> + <structname>pg_stat_lock</structname></link> for details. + </entry> + </row> + <row> <entry><structname>pg_stat_replication_slots</structname><indexterm><primary>pg_stat_replication_slots</primary></indexterm></entry> <entry>One row per replication slot, showing statistics about the @@ -3124,6 +3133,104 @@ description | Waiting for a newly initialized WAL file to reach durable storage </sect2> + + <sect2 id="monitoring-pg-stat-lock-view"> + <title><structname>pg_stat_lock</structname></title> + + <indexterm> + <primary>pg_stat_lock</primary> + </indexterm> + + <para> + The <structname>pg_stat_lock</structname> view will contain one row for each + lock type, showing cluster-wide locks statistics. + </para> + + <table id="pg-stat-lock-view" xreflabel="pg_stat_lock"> + <title><structname>pg_stat_lock</structname> View</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + Column Type + </para> + <para> + Description + </para> + </entry> + </row> + </thead> + <tbody> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>locktype</structfield> <type>text</type> + </para> + <para> + Type of the lockable object. See <link linkend="view-pg-locks"> + <structname>pg_locks</structname></link> for details. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>waits</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type had to wait because of a + conflicting lock. Only incremented when <xref linkend="guc-log-lock-waits"/> + is enabled and the lock was successfully acquired after waiting longer + than <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>wait_time</structfield> <type>bigint</type> + </para> + <para> + Total time spent waiting for locks of this type, in milliseconds. + Only incremented when <xref linkend="guc-log-lock-waits"/> is enabled and + the lock was successfully acquired after waiting longer than + <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>fastpath_exceeded</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type could not be acquired via fast path + because the fast path slot limit was exceeded. You may want to increase + <xref linkend="guc-max-locks-per-transaction"/> if you feel this counter + is too high. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>stats_reset</structfield> <type>timestamp with time zone</type> + </para> + <para> + Time at which these statistics were last reset. + </para> + </entry> + </row> + </tbody> + </tgroup> + </table> + </sect2> + <sect2 id="monitoring-pg-stat-bgwriter-view"> <title><structname>pg_stat_bgwriter</structname></title> @@ -5195,6 +5302,12 @@ description | Waiting for a newly initialized WAL file to reach durable storage <structname>pg_stat_io</structname> view. </para> </listitem> + <listitem> + <para> + <literal>lock</literal>: Reset all the counters shown in the + <structname>pg_stat_lock</structname> view. + </para> + </listitem> <listitem> <para> <literal>recovery_prefetch</literal>: Reset all the counters shown in diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 1ea8f1faa9e..22efeb713e4 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -985,6 +985,15 @@ CREATE VIEW pg_stat_slru AS s.stats_reset FROM pg_stat_get_slru() s; +CREATE VIEW pg_stat_lock AS + SELECT + l.locktype, + l.waits, + l.wait_time, + l.fastpath_exceeded, + l.stats_reset + FROM pg_stat_get_lock() l; + CREATE VIEW pg_stat_wal_receiver AS SELECT s.pid, diff --git a/src/backend/utils/activity/pgstat_lock.c b/src/backend/utils/activity/pgstat_lock.c index 7af4bc6d018..cd4399b5ef6 100644 --- a/src/backend/utils/activity/pgstat_lock.c +++ b/src/backend/utils/activity/pgstat_lock.c @@ -21,6 +21,14 @@ static PgStat_PendingLock PendingLockStats; static bool have_lockstats = false; +PgStat_Lock * +pgstat_fetch_stat_lock(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_LOCK); + + return &pgStatLocal.snapshot.lock; +} + /* * Simpler wrapper of pgstat_lock_flush_cb() */ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index b1df96e7b0b..27ca2d8f07c 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1737,6 +1737,42 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) wal_stats->stat_reset_timestamp)); } +Datum +pg_stat_get_lock(PG_FUNCTION_ARGS) +{ +#define PG_STAT_LOCK_COLS 5 + ReturnSetInfo *rsinfo; + PgStat_Lock *lock_stats; + + InitMaterializedSRF(fcinfo, 0); + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + lock_stats = pgstat_fetch_stat_lock(); + + for (int lcktype = 0; lcktype <= LOCKTAG_LAST_TYPE; lcktype++) + { + const char *locktypename; + Datum values[PG_STAT_LOCK_COLS] = {0}; + bool nulls[PG_STAT_LOCK_COLS] = {0}; + PgStat_LockEntry *lck_stats = &lock_stats->stats[lcktype]; + int i = 0; + + locktypename = LockTagTypeNames[lcktype]; + + values[i++] = CStringGetTextDatum(locktypename); + values[i++] = Int64GetDatum(lck_stats->waits); + values[i++] = Int64GetDatum(lck_stats->wait_time); + values[i++] = Int64GetDatum(lck_stats->fastpath_exceeded); + values[i] = TimestampTzGetDatum(lock_stats->stat_reset_timestamp); + + Assert(i + 1 == PG_STAT_LOCK_COLS); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} + /* * Returns statistics of SLRU caches. */ @@ -1921,6 +1957,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER); pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); pgstat_reset_of_kind(PGSTAT_KIND_IO); + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); @@ -1938,6 +1975,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); else if (strcmp(target, "io") == 0) pgstat_reset_of_kind(PGSTAT_KIND_IO); + else if (strcmp(target, "lock") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); else if (strcmp(target, "recovery_prefetch") == 0) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 83f6501df38..c224e842e32 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6026,6 +6026,15 @@ proargnames => '{backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}', prosrc => 'pg_stat_get_io' }, +{ oid => '9375', descr => 'statistics: per lock type statistics', + proname => 'pg_stat_get_lock', prorows => '10', proretset => 't', + provolatile => 'v', proparallel => 'r', prorettype => 'record', + proargtypes => '', + proallargtypes => '{text,int8,int8,int8,timestamptz}', + proargmodes => '{o,o,o,o,o}', + proargnames => '{locktype,waits,wait_time,fastpath_exceeded,stats_reset}', + prosrc => 'pg_stat_get_lock' }, + { oid => '6386', descr => 'statistics: backend IO statistics', proname => 'pg_stat_get_backend_io', prorows => '5', proretset => 't', provolatile => 'v', proparallel => 'r', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index dfbead474b1..175e431ed81 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -641,6 +641,7 @@ extern void pgstat_lock_flush(bool nowait); extern void pgstat_count_lock_waits(uint8 locktag_type); extern void pgstat_count_lock_fastpath_exceeded(uint8 locktag_type); extern void pgstat_count_lock_wait_time(uint8 locktag_type, long msecs); +extern PgStat_Lock *pgstat_fetch_stat_lock(void); /* * Functions in pgstat_database.c diff --git a/src/test/isolation/expected/stats.out b/src/test/isolation/expected/stats.out index cfad309ccf3..d3cb8715d95 100644 --- a/src/test/isolation/expected/stats.out +++ b/src/test/isolation/expected/stats.out @@ -3751,3 +3751,150 @@ test_stat_func| 1|t |t (1 row) step s1_commit: COMMIT; + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; +?column?|?column? +--------+-------- +t |t +(1 row) + diff --git a/src/test/isolation/expected/stats_1.out b/src/test/isolation/expected/stats_1.out index e1d937784cb..89d2e4cc6b4 100644 --- a/src/test/isolation/expected/stats_1.out +++ b/src/test/isolation/expected/stats_1.out @@ -3775,3 +3775,150 @@ test_stat_func| 1|t |t (1 row) step s1_commit: COMMIT; + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; +?column?|?column? +--------+-------- +t |t +(1 row) + diff --git a/src/test/isolation/specs/stats.spec b/src/test/isolation/specs/stats.spec index da16710da0f..c600fc11157 100644 --- a/src/test/isolation/specs/stats.spec +++ b/src/test/isolation/specs/stats.spec @@ -130,6 +130,14 @@ step s1_slru_check_stats { WHERE before.stat = 'blks_zeroed'; } +# Lock stats steps +step s1_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s1_set_log_lock_waits { SET log_lock_waits = on; } +step s1_reset_stat_lock { SELECT pg_stat_reset_shared('lock'); } +step s1_sleep { SELECT pg_sleep(0.5); } +step s1_lock_relation { LOCK TABLE test_stat_tab; } +step s1_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s1_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } session s2 setup { SET stats_fetch_consistency = 'none'; } @@ -164,6 +172,15 @@ step s2_big_notify { SELECT pg_notify('stats_test_use', repeat(i::text, current_setting('block_size')::int / 2)) FROM generate_series(1, 3) g(i); } +# Lock stats steps +step s2_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s2_set_log_lock_waits { SET log_lock_waits = on; } +step s2_report_stat_lock_relation { SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; } +step s2_report_stat_lock_transactionid { SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; } +step s2_report_stat_lock_advisory { SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; } +step s2_lock_relation { LOCK TABLE test_stat_tab; } +step s2_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s2_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } ###################### # Function stats tests @@ -765,3 +782,62 @@ permutation s1_clear_snapshot s1_func_stats s1_commit + +###################### +# Lock stats tests +###################### + +# relation lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation + +# transaction lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_table_insert + s1_begin + s1_table_update_k1 + s2_begin + s2_ff + s2_table_update_k1 + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_transactionid + +# advisory lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_lock_advisory_lock + s2_begin + s2_ff + s2_lock_advisory_lock + s1_sleep + s1_lock_advisory_unlock + s2_lock_advisory_unlock + s2_commit + s2_report_stat_lock_advisory diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 78a37d9fc8f..c013fbebb88 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1951,6 +1951,12 @@ pg_stat_io| SELECT backend_type, fsync_time, stats_reset FROM pg_stat_get_io() b(backend_type, object, context, reads, read_bytes, read_time, writes, write_bytes, write_time, writebacks, writeback_time, extends, extend_bytes, extend_time, hits, evictions, reuses, fsyncs, fsync_time, stats_reset); +pg_stat_lock| SELECT locktype, + waits, + wait_time, + fastpath_exceeded, + stats_reset + FROM pg_stat_get_lock() l(locktype, waits, wait_time, fastpath_exceeded, stats_reset); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index cd00f35bf7a..ddb016e73d2 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -1910,4 +1910,46 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); (1 row) DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); +SELECT pg_stat_reset_shared('lock'); + pg_stat_reset_shared +---------------------- + +(1 row) + +-- Create 70 partitions (exceeds default number of slots) +DO $$ +BEGIN + FOR i IN 1..70 LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + count +------- + 0 +(1 row) + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + ?column? +---------- + t +(1 row) + +DROP TABLE part_test; -- End of Stats Test diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 8768e0f27fd..fac7d734758 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -944,4 +944,34 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); + +SELECT pg_stat_reset_shared('lock'); + +-- Create 70 partitions (exceeds default number of slots) +DO $$ +BEGIN + FOR i IN 1..70 LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; + +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset + +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + +DROP TABLE part_test; + -- End of Stats Test -- 2.34.1 --n9KlQA279nLbrjqm-- ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v7 2/3] Add the pg_stat_lock view @ 2025-07-31 09:35 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Bertrand Drouvot @ 2025-07-31 09:35 UTC (permalink / raw) This new view reports lock statistics. Note that it does not omit combinations which do not make sense (as pg_locks does). Also wait_time is reported as bigint as the deadlock_timeout default value is 1s. This commit also adds documentation and a few tests. XXX: Bump catversion --- doc/src/sgml/monitoring.sgml | 125 +++++++++++++++ src/backend/catalog/system_views.sql | 10 ++ src/backend/utils/activity/pgstat_lock.c | 8 + src/backend/utils/adt/pgstatfuncs.c | 40 +++++ src/include/catalog/pg_proc.dat | 9 ++ src/include/pgstat.h | 1 + src/test/isolation/expected/stats.out | 189 +++++++++++++++++++++++ src/test/isolation/expected/stats_1.out | 189 +++++++++++++++++++++++ src/test/isolation/specs/stats.spec | 95 ++++++++++++ src/test/regress/expected/rules.out | 7 + src/test/regress/expected/stats.out | 48 ++++++ src/test/regress/sql/stats.sql | 36 +++++ 12 files changed, 757 insertions(+) 16.7% doc/src/sgml/ 5.0% src/backend/utils/adt/ 53.6% src/test/isolation/expected/ 11.1% src/test/isolation/specs/ 5.6% src/test/regress/expected/ 3.9% src/test/regress/sql/ 3.7% src/ diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index b77d189a500..cfcb8189418 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -493,6 +493,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser </entry> </row> + <row> + <entry><structname>pg_stat_lock</structname><indexterm><primary>pg_stat_lock</primary></indexterm></entry> + <entry> + One row for each lock type, containing cluster-wide locks statistics. + See <link linkend="monitoring-pg-stat-lock-view"> + <structname>pg_stat_lock</structname></link> for details. + </entry> + </row> + <row> <entry><structname>pg_stat_replication_slots</structname><indexterm><primary>pg_stat_replication_slots</primary></indexterm></entry> <entry>One row per replication slot, showing statistics about the @@ -3124,6 +3133,116 @@ description | Waiting for a newly initialized WAL file to reach durable storage </sect2> + + <sect2 id="monitoring-pg-stat-lock-view"> + <title><structname>pg_stat_lock</structname></title> + + <indexterm> + <primary>pg_stat_lock</primary> + </indexterm> + + <para> + The <structname>pg_stat_lock</structname> view will contain one row for each + lock type, showing cluster-wide locks statistics. + </para> + + <table id="pg-stat-lock-view" xreflabel="pg_stat_lock"> + <title><structname>pg_stat_lock</structname> View</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + Column Type + </para> + <para> + Description + </para> + </entry> + </row> + </thead> + <tbody> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>locktype</structfield> <type>text</type> + </para> + <para> + Type of the lockable object. See <link linkend="view-pg-locks"> + <structname>pg_locks</structname></link> for details. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>waits</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type had to wait because of a + conflicting lock. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>timed_waits</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type had to wait because of a + conflicting lock. Only incremented when <xref linkend="guc-log-lock-waits"/> + is enabled and the lock was successfully acquired after waiting longer + than <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>wait_time</structfield> <type>bigint</type> + </para> + <para> + Total time spent waiting for locks of this type, in milliseconds. + Only incremented when <xref linkend="guc-log-lock-waits"/> is enabled and + the lock was successfully acquired after waiting longer than + <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>fastpath_exceeded</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type could not be acquired via fast path + because the fast path slot limit was exceeded. You may want to increase + <xref linkend="guc-max-locks-per-transaction"/> if you feel this counter + is too high. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>stats_reset</structfield> <type>timestamp with time zone</type> + </para> + <para> + Time at which these statistics were last reset. + </para> + </entry> + </row> + </tbody> + </tgroup> + </table> + </sect2> + <sect2 id="monitoring-pg-stat-bgwriter-view"> <title><structname>pg_stat_bgwriter</structname></title> @@ -5195,6 +5314,12 @@ description | Waiting for a newly initialized WAL file to reach durable storage <structname>pg_stat_io</structname> view. </para> </listitem> + <listitem> + <para> + <literal>lock</literal>: Reset all the counters shown in the + <structname>pg_stat_lock</structname> view. + </para> + </listitem> <listitem> <para> <literal>recovery_prefetch</literal>: Reset all the counters shown in diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 1ea8f1faa9e..dcf12a202e0 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -985,6 +985,16 @@ CREATE VIEW pg_stat_slru AS s.stats_reset FROM pg_stat_get_slru() s; +CREATE VIEW pg_stat_lock AS + SELECT + l.locktype, + l.waits, + l.timed_waits, + l.wait_time, + l.fastpath_exceeded, + l.stats_reset + FROM pg_stat_get_lock() l; + CREATE VIEW pg_stat_wal_receiver AS SELECT s.pid, diff --git a/src/backend/utils/activity/pgstat_lock.c b/src/backend/utils/activity/pgstat_lock.c index b410f376d49..451fba4f8d9 100644 --- a/src/backend/utils/activity/pgstat_lock.c +++ b/src/backend/utils/activity/pgstat_lock.c @@ -21,6 +21,14 @@ static PgStat_PendingLock PendingLockStats; static bool have_lockstats = false; +PgStat_Lock * +pgstat_fetch_stat_lock(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_LOCK); + + return &pgStatLocal.snapshot.lock; +} + /* * Simpler wrapper of pgstat_lock_flush_cb() */ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index b1df96e7b0b..3b7cbdb82be 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1737,6 +1737,43 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) wal_stats->stat_reset_timestamp)); } +Datum +pg_stat_get_lock(PG_FUNCTION_ARGS) +{ +#define PG_STAT_LOCK_COLS 6 + ReturnSetInfo *rsinfo; + PgStat_Lock *lock_stats; + + InitMaterializedSRF(fcinfo, 0); + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + lock_stats = pgstat_fetch_stat_lock(); + + for (int lcktype = 0; lcktype <= LOCKTAG_LAST_TYPE; lcktype++) + { + const char *locktypename; + Datum values[PG_STAT_LOCK_COLS] = {0}; + bool nulls[PG_STAT_LOCK_COLS] = {0}; + PgStat_LockEntry *lck_stats = &lock_stats->stats[lcktype]; + int i = 0; + + locktypename = LockTagTypeNames[lcktype]; + + values[i++] = CStringGetTextDatum(locktypename); + values[i++] = Int64GetDatum(lck_stats->waits); + values[i++] = Int64GetDatum(lck_stats->timed_waits); + values[i++] = Int64GetDatum(lck_stats->wait_time); + values[i++] = Int64GetDatum(lck_stats->fastpath_exceeded); + values[i] = TimestampTzGetDatum(lock_stats->stat_reset_timestamp); + + Assert(i + 1 == PG_STAT_LOCK_COLS); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} + /* * Returns statistics of SLRU caches. */ @@ -1921,6 +1958,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER); pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); pgstat_reset_of_kind(PGSTAT_KIND_IO); + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); @@ -1938,6 +1976,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); else if (strcmp(target, "io") == 0) pgstat_reset_of_kind(PGSTAT_KIND_IO); + else if (strcmp(target, "lock") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); else if (strcmp(target, "recovery_prefetch") == 0) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index dac40992cbc..3cd497a8e1f 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6027,6 +6027,15 @@ proargnames => '{backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}', prosrc => 'pg_stat_get_io' }, +{ oid => '9375', descr => 'statistics: per lock type statistics', + proname => 'pg_stat_get_lock', prorows => '10', proretset => 't', + provolatile => 'v', proparallel => 'r', prorettype => 'record', + proargtypes => '', + proallargtypes => '{text,int8,int8,int8,int8,timestamptz}', + proargmodes => '{o,o,o,o,o,o}', + proargnames => '{locktype,waits,timed_waits,wait_time,fastpath_exceeded,stats_reset}', + prosrc => 'pg_stat_get_lock' }, + { oid => '6386', descr => 'statistics: backend IO statistics', proname => 'pg_stat_get_backend_io', prorows => '5', proretset => 't', provolatile => 'v', proparallel => 'r', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 9c4508d5544..a4cc006794d 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -641,6 +641,7 @@ extern void pgstat_lock_flush(bool nowait); extern void pgstat_count_lock_waits(uint8 locktag_type); extern void pgstat_count_lock_fastpath_exceeded(uint8 locktag_type); extern void pgstat_count_lock_timed_wait(uint8 locktag_type, long msecs); +extern PgStat_Lock *pgstat_fetch_stat_lock(void); /* * Functions in pgstat_database.c diff --git a/src/test/isolation/expected/stats.out b/src/test/isolation/expected/stats.out index cfad309ccf3..86d70a0705c 100644 --- a/src/test/isolation/expected/stats.out +++ b/src/test/isolation/expected/stats.out @@ -3751,3 +3751,192 @@ test_stat_func| 1|t |t (1 row) step s1_commit: COMMIT; + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column?|?column? +--------+--------+-------- +t |t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; +?column?|?column?|?column? +--------+--------+-------- +t |t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; +?column?|?column?|?column? +--------+--------+-------- +t |t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_unset_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_unset_log_lock_waits: SET log_lock_waits = off; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column?|?column? +--------+--------+-------- +t |f |f +(1 row) + diff --git a/src/test/isolation/expected/stats_1.out b/src/test/isolation/expected/stats_1.out index e1d937784cb..4e4c68b4525 100644 --- a/src/test/isolation/expected/stats_1.out +++ b/src/test/isolation/expected/stats_1.out @@ -3775,3 +3775,192 @@ test_stat_func| 1|t |t (1 row) step s1_commit: COMMIT; + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column?|?column? +--------+--------+-------- +t |t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; +?column?|?column?|?column? +--------+--------+-------- +t |t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; +?column?|?column?|?column? +--------+--------+-------- +t |t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_unset_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_unset_log_lock_waits: SET log_lock_waits = off; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column?|?column? +--------+--------+-------- +t |f |f +(1 row) + diff --git a/src/test/isolation/specs/stats.spec b/src/test/isolation/specs/stats.spec index da16710da0f..d4b53545198 100644 --- a/src/test/isolation/specs/stats.spec +++ b/src/test/isolation/specs/stats.spec @@ -130,6 +130,14 @@ step s1_slru_check_stats { WHERE before.stat = 'blks_zeroed'; } +# Lock stats steps +step s1_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s1_set_log_lock_waits { SET log_lock_waits = on; } +step s1_reset_stat_lock { SELECT pg_stat_reset_shared('lock'); } +step s1_sleep { SELECT pg_sleep(0.5); } +step s1_lock_relation { LOCK TABLE test_stat_tab; } +step s1_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s1_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } session s2 setup { SET stats_fetch_consistency = 'none'; } @@ -164,6 +172,16 @@ step s2_big_notify { SELECT pg_notify('stats_test_use', repeat(i::text, current_setting('block_size')::int / 2)) FROM generate_series(1, 3) g(i); } +# Lock stats steps +step s2_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s2_set_log_lock_waits { SET log_lock_waits = on; } +step s2_unset_log_lock_waits { SET log_lock_waits = off; } +step s2_report_stat_lock_relation { SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; } +step s2_report_stat_lock_transactionid { SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; } +step s2_report_stat_lock_advisory { SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; } +step s2_lock_relation { LOCK TABLE test_stat_tab; } +step s2_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s2_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } ###################### # Function stats tests @@ -765,3 +783,80 @@ permutation s1_clear_snapshot s1_func_stats s1_commit + +###################### +# Lock stats tests +###################### + +# relation lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation + +# transaction lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_table_insert + s1_begin + s1_table_update_k1 + s2_begin + s2_ff + s2_table_update_k1 + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_transactionid + +# advisory lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_lock_advisory_lock + s2_begin + s2_ff + s2_lock_advisory_lock + s1_sleep + s1_lock_advisory_unlock + s2_lock_advisory_unlock + s2_commit + s2_report_stat_lock_advisory + +# Ensure log_lock_waits behaves correctly + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_unset_log_lock_waits + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 78a37d9fc8f..2fcb48df6c9 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1951,6 +1951,13 @@ pg_stat_io| SELECT backend_type, fsync_time, stats_reset FROM pg_stat_get_io() b(backend_type, object, context, reads, read_bytes, read_time, writes, write_bytes, write_time, writebacks, writeback_time, extends, extend_bytes, extend_time, hits, evictions, reuses, fsyncs, fsync_time, stats_reset); +pg_stat_lock| SELECT locktype, + waits, + timed_waits, + wait_time, + fastpath_exceeded, + stats_reset + FROM pg_stat_get_lock() l(locktype, waits, timed_waits, wait_time, fastpath_exceeded, stats_reset); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index cd00f35bf7a..93de87747d4 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -1910,4 +1910,52 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); (1 row) DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); +SELECT pg_stat_reset_shared('lock'); + pg_stat_reset_shared +---------------------- + +(1 row) + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + count +------- + 0 +(1 row) + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + ?column? +---------- + t +(1 row) + +DROP TABLE part_test; -- End of Stats Test diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 8768e0f27fd..db9948eedb8 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -944,4 +944,40 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); + +SELECT pg_stat_reset_shared('lock'); + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; + +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset + +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + +DROP TABLE part_test; + -- End of Stats Test -- 2.34.1 --gJ14Jcshhoq1cFBD Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v7-0003-Introduce-a-new-track_lock_timing-GUC.patch" ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v8 2/3] Add the pg_stat_lock view @ 2025-07-31 09:35 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Bertrand Drouvot @ 2025-07-31 09:35 UTC (permalink / raw) This new view reports lock statistics. Note that it does not omit combinations which do not make sense (as pg_locks does). Also wait_time is reported as bigint as the deadlock_timeout default value is 1s. This commit also adds documentation and a few tests. XXX: Bump catversion --- doc/src/sgml/monitoring.sgml | 113 ++++++++++++++ src/backend/catalog/system_views.sql | 9 ++ src/backend/utils/activity/pgstat_lock.c | 8 + src/backend/utils/adt/pgstatfuncs.c | 39 +++++ src/include/catalog/pg_proc.dat | 9 ++ src/include/pgstat.h | 1 + src/test/isolation/expected/stats.out | 189 +++++++++++++++++++++++ src/test/isolation/expected/stats_1.out | 189 +++++++++++++++++++++++ src/test/isolation/specs/stats.spec | 95 ++++++++++++ src/test/regress/expected/rules.out | 6 + src/test/regress/expected/stats.out | 48 ++++++ src/test/regress/sql/stats.sql | 36 +++++ 12 files changed, 742 insertions(+) 15.9% doc/src/sgml/ 5.0% src/backend/utils/adt/ 54.1% src/test/isolation/expected/ 11.3% src/test/isolation/specs/ 5.7% src/test/regress/expected/ 4.0% src/test/regress/sql/ 3.6% src/ diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index b77d189a500..3a196bc305c 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -493,6 +493,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser </entry> </row> + <row> + <entry><structname>pg_stat_lock</structname><indexterm><primary>pg_stat_lock</primary></indexterm></entry> + <entry> + One row for each lock type, containing cluster-wide locks statistics. + See <link linkend="monitoring-pg-stat-lock-view"> + <structname>pg_stat_lock</structname></link> for details. + </entry> + </row> + <row> <entry><structname>pg_stat_replication_slots</structname><indexterm><primary>pg_stat_replication_slots</primary></indexterm></entry> <entry>One row per replication slot, showing statistics about the @@ -3124,6 +3133,104 @@ description | Waiting for a newly initialized WAL file to reach durable storage </sect2> + + <sect2 id="monitoring-pg-stat-lock-view"> + <title><structname>pg_stat_lock</structname></title> + + <indexterm> + <primary>pg_stat_lock</primary> + </indexterm> + + <para> + The <structname>pg_stat_lock</structname> view will contain one row for each + lock type, showing cluster-wide locks statistics. + </para> + + <table id="pg-stat-lock-view" xreflabel="pg_stat_lock"> + <title><structname>pg_stat_lock</structname> View</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + Column Type + </para> + <para> + Description + </para> + </entry> + </row> + </thead> + <tbody> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>locktype</structfield> <type>text</type> + </para> + <para> + Type of the lockable object. See <link linkend="view-pg-locks"> + <structname>pg_locks</structname></link> for details. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>waits</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type had to wait because of a + conflicting lock. Only incremented when <xref linkend="guc-log-lock-waits"/> + is enabled and the lock was successfully acquired after waiting longer + than <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>wait_time</structfield> <type>bigint</type> + </para> + <para> + Total time spent waiting for locks of this type, in milliseconds. + Only incremented when <xref linkend="guc-log-lock-waits"/> is enabled and + the lock was successfully acquired after waiting longer than + <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>fastpath_exceeded</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type could not be acquired via fast path + because the fast path slot limit was exceeded. You may want to increase + <xref linkend="guc-max-locks-per-transaction"/> if you feel this counter + is too high. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>stats_reset</structfield> <type>timestamp with time zone</type> + </para> + <para> + Time at which these statistics were last reset. + </para> + </entry> + </row> + </tbody> + </tgroup> + </table> + </sect2> + <sect2 id="monitoring-pg-stat-bgwriter-view"> <title><structname>pg_stat_bgwriter</structname></title> @@ -5195,6 +5302,12 @@ description | Waiting for a newly initialized WAL file to reach durable storage <structname>pg_stat_io</structname> view. </para> </listitem> + <listitem> + <para> + <literal>lock</literal>: Reset all the counters shown in the + <structname>pg_stat_lock</structname> view. + </para> + </listitem> <listitem> <para> <literal>recovery_prefetch</literal>: Reset all the counters shown in diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 1ea8f1faa9e..22efeb713e4 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -985,6 +985,15 @@ CREATE VIEW pg_stat_slru AS s.stats_reset FROM pg_stat_get_slru() s; +CREATE VIEW pg_stat_lock AS + SELECT + l.locktype, + l.waits, + l.wait_time, + l.fastpath_exceeded, + l.stats_reset + FROM pg_stat_get_lock() l; + CREATE VIEW pg_stat_wal_receiver AS SELECT s.pid, diff --git a/src/backend/utils/activity/pgstat_lock.c b/src/backend/utils/activity/pgstat_lock.c index 91a53a6013a..954fa51c3e0 100644 --- a/src/backend/utils/activity/pgstat_lock.c +++ b/src/backend/utils/activity/pgstat_lock.c @@ -21,6 +21,14 @@ static PgStat_PendingLock PendingLockStats; static bool have_lockstats = false; +PgStat_Lock * +pgstat_fetch_stat_lock(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_LOCK); + + return &pgStatLocal.snapshot.lock; +} + /* * Simpler wrapper of pgstat_lock_flush_cb() */ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index b1df96e7b0b..27ca2d8f07c 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1737,6 +1737,42 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) wal_stats->stat_reset_timestamp)); } +Datum +pg_stat_get_lock(PG_FUNCTION_ARGS) +{ +#define PG_STAT_LOCK_COLS 5 + ReturnSetInfo *rsinfo; + PgStat_Lock *lock_stats; + + InitMaterializedSRF(fcinfo, 0); + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + lock_stats = pgstat_fetch_stat_lock(); + + for (int lcktype = 0; lcktype <= LOCKTAG_LAST_TYPE; lcktype++) + { + const char *locktypename; + Datum values[PG_STAT_LOCK_COLS] = {0}; + bool nulls[PG_STAT_LOCK_COLS] = {0}; + PgStat_LockEntry *lck_stats = &lock_stats->stats[lcktype]; + int i = 0; + + locktypename = LockTagTypeNames[lcktype]; + + values[i++] = CStringGetTextDatum(locktypename); + values[i++] = Int64GetDatum(lck_stats->waits); + values[i++] = Int64GetDatum(lck_stats->wait_time); + values[i++] = Int64GetDatum(lck_stats->fastpath_exceeded); + values[i] = TimestampTzGetDatum(lock_stats->stat_reset_timestamp); + + Assert(i + 1 == PG_STAT_LOCK_COLS); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} + /* * Returns statistics of SLRU caches. */ @@ -1921,6 +1957,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER); pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); pgstat_reset_of_kind(PGSTAT_KIND_IO); + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); @@ -1938,6 +1975,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); else if (strcmp(target, "io") == 0) pgstat_reset_of_kind(PGSTAT_KIND_IO); + else if (strcmp(target, "lock") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); else if (strcmp(target, "recovery_prefetch") == 0) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index dac40992cbc..daeb45704c6 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6027,6 +6027,15 @@ proargnames => '{backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}', prosrc => 'pg_stat_get_io' }, +{ oid => '9375', descr => 'statistics: per lock type statistics', + proname => 'pg_stat_get_lock', prorows => '10', proretset => 't', + provolatile => 'v', proparallel => 'r', prorettype => 'record', + proargtypes => '', + proallargtypes => '{text,int8,int8,int8,timestamptz}', + proargmodes => '{o,o,o,o,o}', + proargnames => '{locktype,waits,wait_time,fastpath_exceeded,stats_reset}', + prosrc => 'pg_stat_get_lock' }, + { oid => '6386', descr => 'statistics: backend IO statistics', proname => 'pg_stat_get_backend_io', prorows => '5', proretset => 't', provolatile => 'v', proparallel => 'r', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index f563132bf7b..1c261e2c7a8 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -644,6 +644,7 @@ extern bool pgstat_tracks_io_op(BackendType bktype, IOObject io_object, extern void pgstat_lock_flush(bool nowait); extern void pgstat_count_lock_fastpath_exceeded(uint8 locktag_type); extern void pgstat_count_lock_waits(uint8 locktag_type, long msecs); +extern PgStat_Lock *pgstat_fetch_stat_lock(void); /* * Functions in pgstat_database.c diff --git a/src/test/isolation/expected/stats.out b/src/test/isolation/expected/stats.out index cfad309ccf3..3cae3052e40 100644 --- a/src/test/isolation/expected/stats.out +++ b/src/test/isolation/expected/stats.out @@ -3751,3 +3751,192 @@ test_stat_func| 1|t |t (1 row) step s1_commit: COMMIT; + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_unset_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_unset_log_lock_waits: SET log_lock_waits = off; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +f |f +(1 row) + diff --git a/src/test/isolation/expected/stats_1.out b/src/test/isolation/expected/stats_1.out index e1d937784cb..ea4fd97a9a5 100644 --- a/src/test/isolation/expected/stats_1.out +++ b/src/test/isolation/expected/stats_1.out @@ -3775,3 +3775,192 @@ test_stat_func| 1|t |t (1 row) step s1_commit: COMMIT; + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_unset_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_unset_log_lock_waits: SET log_lock_waits = off; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +f |f +(1 row) + diff --git a/src/test/isolation/specs/stats.spec b/src/test/isolation/specs/stats.spec index da16710da0f..42be68c545f 100644 --- a/src/test/isolation/specs/stats.spec +++ b/src/test/isolation/specs/stats.spec @@ -130,6 +130,14 @@ step s1_slru_check_stats { WHERE before.stat = 'blks_zeroed'; } +# Lock stats steps +step s1_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s1_set_log_lock_waits { SET log_lock_waits = on; } +step s1_reset_stat_lock { SELECT pg_stat_reset_shared('lock'); } +step s1_sleep { SELECT pg_sleep(0.5); } +step s1_lock_relation { LOCK TABLE test_stat_tab; } +step s1_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s1_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } session s2 setup { SET stats_fetch_consistency = 'none'; } @@ -164,6 +172,16 @@ step s2_big_notify { SELECT pg_notify('stats_test_use', repeat(i::text, current_setting('block_size')::int / 2)) FROM generate_series(1, 3) g(i); } +# Lock stats steps +step s2_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s2_set_log_lock_waits { SET log_lock_waits = on; } +step s2_unset_log_lock_waits { SET log_lock_waits = off; } +step s2_report_stat_lock_relation { SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; } +step s2_report_stat_lock_transactionid { SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; } +step s2_report_stat_lock_advisory { SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; } +step s2_lock_relation { LOCK TABLE test_stat_tab; } +step s2_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s2_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } ###################### # Function stats tests @@ -765,3 +783,80 @@ permutation s1_clear_snapshot s1_func_stats s1_commit + +###################### +# Lock stats tests +###################### + +# relation lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation + +# transaction lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_table_insert + s1_begin + s1_table_update_k1 + s2_begin + s2_ff + s2_table_update_k1 + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_transactionid + +# advisory lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_lock_advisory_lock + s2_begin + s2_ff + s2_lock_advisory_lock + s1_sleep + s1_lock_advisory_unlock + s2_lock_advisory_unlock + s2_commit + s2_report_stat_lock_advisory + +# Ensure log_lock_waits behaves correctly + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_unset_log_lock_waits + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 78a37d9fc8f..c013fbebb88 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1951,6 +1951,12 @@ pg_stat_io| SELECT backend_type, fsync_time, stats_reset FROM pg_stat_get_io() b(backend_type, object, context, reads, read_bytes, read_time, writes, write_bytes, write_time, writebacks, writeback_time, extends, extend_bytes, extend_time, hits, evictions, reuses, fsyncs, fsync_time, stats_reset); +pg_stat_lock| SELECT locktype, + waits, + wait_time, + fastpath_exceeded, + stats_reset + FROM pg_stat_get_lock() l(locktype, waits, wait_time, fastpath_exceeded, stats_reset); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index cd00f35bf7a..93de87747d4 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -1910,4 +1910,52 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); (1 row) DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); +SELECT pg_stat_reset_shared('lock'); + pg_stat_reset_shared +---------------------- + +(1 row) + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + count +------- + 0 +(1 row) + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + ?column? +---------- + t +(1 row) + +DROP TABLE part_test; -- End of Stats Test diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 8768e0f27fd..db9948eedb8 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -944,4 +944,40 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); + +SELECT pg_stat_reset_shared('lock'); + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; + +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset + +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + +DROP TABLE part_test; + -- End of Stats Test -- 2.34.1 --CwwtKyeZcJiDzEBE Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v8-0003-Introduce-a-new-track_lock_timing-GUC.patch" ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v9 2/3] Add the pg_stat_lock view @ 2025-07-31 09:35 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Bertrand Drouvot @ 2025-07-31 09:35 UTC (permalink / raw) This new view reports lock statistics. Note that it does not omit combinations which do not make sense (as pg_locks does). Also wait_time is reported as bigint as the deadlock_timeout default value is 1s. This commit also adds documentation and a few tests. XXX: Bump catversion --- doc/src/sgml/monitoring.sgml | 113 ++++++++++++++ src/backend/catalog/system_views.sql | 9 ++ src/backend/utils/activity/pgstat_lock.c | 8 + src/backend/utils/adt/pgstatfuncs.c | 39 +++++ src/include/catalog/pg_proc.dat | 9 ++ src/include/pgstat.h | 1 + src/test/isolation/expected/stats.out | 189 +++++++++++++++++++++++ src/test/isolation/expected/stats_1.out | 189 +++++++++++++++++++++++ src/test/isolation/specs/stats.spec | 95 ++++++++++++ src/test/regress/expected/rules.out | 6 + src/test/regress/expected/stats.out | 48 ++++++ src/test/regress/sql/stats.sql | 36 +++++ 12 files changed, 742 insertions(+) 15.9% doc/src/sgml/ 5.0% src/backend/utils/adt/ 54.1% src/test/isolation/expected/ 11.3% src/test/isolation/specs/ 5.7% src/test/regress/expected/ 4.0% src/test/regress/sql/ 3.6% src/ diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 462019a972c..221ee28cc7b 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -509,6 +509,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser </entry> </row> + <row> + <entry><structname>pg_stat_lock</structname><indexterm><primary>pg_stat_lock</primary></indexterm></entry> + <entry> + One row for each lock type, containing cluster-wide locks statistics. + See <link linkend="monitoring-pg-stat-lock-view"> + <structname>pg_stat_lock</structname></link> for details. + </entry> + </row> + <row> <entry><structname>pg_stat_replication_slots</structname><indexterm><primary>pg_stat_replication_slots</primary></indexterm></entry> <entry>One row per replication slot, showing statistics about the @@ -3283,6 +3292,104 @@ description | Waiting for a newly initialized WAL file to reach durable storage </sect2> + + <sect2 id="monitoring-pg-stat-lock-view"> + <title><structname>pg_stat_lock</structname></title> + + <indexterm> + <primary>pg_stat_lock</primary> + </indexterm> + + <para> + The <structname>pg_stat_lock</structname> view will contain one row for each + lock type, showing cluster-wide locks statistics. + </para> + + <table id="pg-stat-lock-view" xreflabel="pg_stat_lock"> + <title><structname>pg_stat_lock</structname> View</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + Column Type + </para> + <para> + Description + </para> + </entry> + </row> + </thead> + <tbody> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>locktype</structfield> <type>text</type> + </para> + <para> + Type of the lockable object. See <link linkend="view-pg-locks"> + <structname>pg_locks</structname></link> for details. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>waits</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type had to wait because of a + conflicting lock. Only incremented when <xref linkend="guc-log-lock-waits"/> + is enabled and the lock was successfully acquired after waiting longer + than <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>wait_time</structfield> <type>bigint</type> + </para> + <para> + Total time spent waiting for locks of this type, in milliseconds. + Only incremented when <xref linkend="guc-log-lock-waits"/> is enabled and + the lock was successfully acquired after waiting longer than + <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>fastpath_exceeded</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type could not be acquired via fast path + because the fast path slot limit was exceeded. You may want to increase + <xref linkend="guc-max-locks-per-transaction"/> if you feel this counter + is too high. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>stats_reset</structfield> <type>timestamp with time zone</type> + </para> + <para> + Time at which these statistics were last reset. + </para> + </entry> + </row> + </tbody> + </tgroup> + </table> + </sect2> + <sect2 id="monitoring-pg-stat-bgwriter-view"> <title><structname>pg_stat_bgwriter</structname></title> @@ -5372,6 +5479,12 @@ description | Waiting for a newly initialized WAL file to reach durable storage <structname>pg_stat_io</structname> view. </para> </listitem> + <listitem> + <para> + <literal>lock</literal>: Reset all the counters shown in the + <structname>pg_stat_lock</structname> view. + </para> + </listitem> <listitem> <para> <literal>recovery_prefetch</literal>: Reset all the counters shown in diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index f1ed7b58f13..e54018004db 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -985,6 +985,15 @@ CREATE VIEW pg_stat_slru AS s.stats_reset FROM pg_stat_get_slru() s; +CREATE VIEW pg_stat_lock AS + SELECT + l.locktype, + l.waits, + l.wait_time, + l.fastpath_exceeded, + l.stats_reset + FROM pg_stat_get_lock() l; + CREATE VIEW pg_stat_wal_receiver AS SELECT s.pid, diff --git a/src/backend/utils/activity/pgstat_lock.c b/src/backend/utils/activity/pgstat_lock.c index 91a53a6013a..954fa51c3e0 100644 --- a/src/backend/utils/activity/pgstat_lock.c +++ b/src/backend/utils/activity/pgstat_lock.c @@ -21,6 +21,14 @@ static PgStat_PendingLock PendingLockStats; static bool have_lockstats = false; +PgStat_Lock * +pgstat_fetch_stat_lock(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_LOCK); + + return &pgStatLocal.snapshot.lock; +} + /* * Simpler wrapper of pgstat_lock_flush_cb() */ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 5f907335990..9185a8e6b83 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1741,6 +1741,42 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) wal_stats->stat_reset_timestamp)); } +Datum +pg_stat_get_lock(PG_FUNCTION_ARGS) +{ +#define PG_STAT_LOCK_COLS 5 + ReturnSetInfo *rsinfo; + PgStat_Lock *lock_stats; + + InitMaterializedSRF(fcinfo, 0); + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + lock_stats = pgstat_fetch_stat_lock(); + + for (int lcktype = 0; lcktype <= LOCKTAG_LAST_TYPE; lcktype++) + { + const char *locktypename; + Datum values[PG_STAT_LOCK_COLS] = {0}; + bool nulls[PG_STAT_LOCK_COLS] = {0}; + PgStat_LockEntry *lck_stats = &lock_stats->stats[lcktype]; + int i = 0; + + locktypename = LockTagTypeNames[lcktype]; + + values[i++] = CStringGetTextDatum(locktypename); + values[i++] = Int64GetDatum(lck_stats->waits); + values[i++] = Int64GetDatum(lck_stats->wait_time); + values[i++] = Int64GetDatum(lck_stats->fastpath_exceeded); + values[i] = TimestampTzGetDatum(lock_stats->stat_reset_timestamp); + + Assert(i + 1 == PG_STAT_LOCK_COLS); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} + /* * Returns statistics of SLRU caches. */ @@ -1925,6 +1961,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER); pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); pgstat_reset_of_kind(PGSTAT_KIND_IO); + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); @@ -1942,6 +1979,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); else if (strcmp(target, "io") == 0) pgstat_reset_of_kind(PGSTAT_KIND_IO); + else if (strcmp(target, "lock") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); else if (strcmp(target, "recovery_prefetch") == 0) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index fc8d82665b8..3e2c43e9d1b 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6041,6 +6041,15 @@ proargnames => '{backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}', prosrc => 'pg_stat_get_io' }, +{ oid => '9375', descr => 'statistics: per lock type statistics', + proname => 'pg_stat_get_lock', prorows => '10', proretset => 't', + provolatile => 'v', proparallel => 'r', prorettype => 'record', + proargtypes => '', + proallargtypes => '{text,int8,int8,int8,timestamptz}', + proargmodes => '{o,o,o,o,o}', + proargnames => '{locktype,waits,wait_time,fastpath_exceeded,stats_reset}', + prosrc => 'pg_stat_get_lock' }, + { oid => '6386', descr => 'statistics: backend IO statistics', proname => 'pg_stat_get_backend_io', prorows => '5', proretset => 't', provolatile => 'v', proparallel => 'r', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 4a28ea99705..06e2638e788 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -643,6 +643,7 @@ extern bool pgstat_tracks_io_op(BackendType bktype, IOObject io_object, extern void pgstat_lock_flush(bool nowait); extern void pgstat_count_lock_fastpath_exceeded(uint8 locktag_type); extern void pgstat_count_lock_waits(uint8 locktag_type, long msecs); +extern PgStat_Lock *pgstat_fetch_stat_lock(void); /* * Functions in pgstat_database.c diff --git a/src/test/isolation/expected/stats.out b/src/test/isolation/expected/stats.out index cfad309ccf3..3cae3052e40 100644 --- a/src/test/isolation/expected/stats.out +++ b/src/test/isolation/expected/stats.out @@ -3751,3 +3751,192 @@ test_stat_func| 1|t |t (1 row) step s1_commit: COMMIT; + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_unset_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_unset_log_lock_waits: SET log_lock_waits = off; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +f |f +(1 row) + diff --git a/src/test/isolation/expected/stats_1.out b/src/test/isolation/expected/stats_1.out index e1d937784cb..ea4fd97a9a5 100644 --- a/src/test/isolation/expected/stats_1.out +++ b/src/test/isolation/expected/stats_1.out @@ -3775,3 +3775,192 @@ test_stat_func| 1|t |t (1 row) step s1_commit: COMMIT; + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_unset_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_unset_log_lock_waits: SET log_lock_waits = off; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +f |f +(1 row) + diff --git a/src/test/isolation/specs/stats.spec b/src/test/isolation/specs/stats.spec index da16710da0f..42be68c545f 100644 --- a/src/test/isolation/specs/stats.spec +++ b/src/test/isolation/specs/stats.spec @@ -130,6 +130,14 @@ step s1_slru_check_stats { WHERE before.stat = 'blks_zeroed'; } +# Lock stats steps +step s1_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s1_set_log_lock_waits { SET log_lock_waits = on; } +step s1_reset_stat_lock { SELECT pg_stat_reset_shared('lock'); } +step s1_sleep { SELECT pg_sleep(0.5); } +step s1_lock_relation { LOCK TABLE test_stat_tab; } +step s1_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s1_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } session s2 setup { SET stats_fetch_consistency = 'none'; } @@ -164,6 +172,16 @@ step s2_big_notify { SELECT pg_notify('stats_test_use', repeat(i::text, current_setting('block_size')::int / 2)) FROM generate_series(1, 3) g(i); } +# Lock stats steps +step s2_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s2_set_log_lock_waits { SET log_lock_waits = on; } +step s2_unset_log_lock_waits { SET log_lock_waits = off; } +step s2_report_stat_lock_relation { SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; } +step s2_report_stat_lock_transactionid { SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; } +step s2_report_stat_lock_advisory { SELECT waits > 0, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; } +step s2_lock_relation { LOCK TABLE test_stat_tab; } +step s2_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s2_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } ###################### # Function stats tests @@ -765,3 +783,80 @@ permutation s1_clear_snapshot s1_func_stats s1_commit + +###################### +# Lock stats tests +###################### + +# relation lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation + +# transaction lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_table_insert + s1_begin + s1_table_update_k1 + s2_begin + s2_ff + s2_table_update_k1 + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_transactionid + +# advisory lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_lock_advisory_lock + s2_begin + s2_ff + s2_lock_advisory_lock + s1_sleep + s1_lock_advisory_unlock + s2_lock_advisory_unlock + s2_commit + s2_report_stat_lock_advisory + +# Ensure log_lock_waits behaves correctly + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_unset_log_lock_waits + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 32bea58db2c..2b3cf6d8569 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1952,6 +1952,12 @@ pg_stat_io| SELECT backend_type, fsync_time, stats_reset FROM pg_stat_get_io() b(backend_type, object, context, reads, read_bytes, read_time, writes, write_bytes, write_time, writebacks, writeback_time, extends, extend_bytes, extend_time, hits, evictions, reuses, fsyncs, fsync_time, stats_reset); +pg_stat_lock| SELECT locktype, + waits, + wait_time, + fastpath_exceeded, + stats_reset + FROM pg_stat_get_lock() l(locktype, waits, wait_time, fastpath_exceeded, stats_reset); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index b99462bf946..ea7f7846895 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -1958,4 +1958,52 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); (1 row) DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); +SELECT pg_stat_reset_shared('lock'); + pg_stat_reset_shared +---------------------- + +(1 row) + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + count +------- + 0 +(1 row) + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + ?column? +---------- + t +(1 row) + +DROP TABLE part_test; -- End of Stats Test diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 941222cf0be..65d8968c83e 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -964,4 +964,40 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); + +SELECT pg_stat_reset_shared('lock'); + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; + +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset + +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + +DROP TABLE part_test; + -- End of Stats Test -- 2.34.1 --nK2xgkLTeiiswcxd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v9-0003-Introduce-a-new-track_lock_timing-GUC.patch" ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v10 2/2] Add the pg_stat_lock view @ 2025-07-31 09:35 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Bertrand Drouvot @ 2025-07-31 09:35 UTC (permalink / raw) This new view reports lock statistics. Note that it does not omit combinations which do not make sense (as pg_locks does). Also wait_time is reported as bigint as the deadlock_timeout default value is 1s. This commit also adds documentation and a few tests. XXX: Bump catversion Author: Bertrand Drouvot <[email protected]> Reviewed-by: Andres Freund <[email protected]> Discussion: https://postgr.es/m/aIyNxBWFCybgBZBS%40ip-10-97-1-34.eu-west-3.compute.internal --- doc/src/sgml/monitoring.sgml | 113 ++++++++++++ src/backend/catalog/system_views.sql | 9 + src/backend/utils/activity/pgstat_lock.c | 8 + src/backend/utils/adt/pgstatfuncs.c | 39 +++++ src/include/catalog/pg_proc.dat | 9 + src/include/pgstat.h | 1 + src/test/isolation/expected/lock-stats.out | 190 +++++++++++++++++++++ src/test/isolation/isolation_schedule | 1 + src/test/isolation/specs/lock-stats.spec | 118 +++++++++++++ src/test/regress/expected/rules.out | 6 + src/test/regress/expected/stats.out | 48 ++++++ src/test/regress/sql/stats.sql | 36 ++++ 12 files changed, 578 insertions(+) 20.8% doc/src/sgml/ 6.5% src/backend/utils/adt/ 35.5% src/test/isolation/expected/ 19.1% src/test/isolation/specs/ 7.5% src/test/regress/expected/ 5.3% src/test/regress/sql/ 4.9% src/ diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 462019a972c..221ee28cc7b 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -509,6 +509,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser </entry> </row> + <row> + <entry><structname>pg_stat_lock</structname><indexterm><primary>pg_stat_lock</primary></indexterm></entry> + <entry> + One row for each lock type, containing cluster-wide locks statistics. + See <link linkend="monitoring-pg-stat-lock-view"> + <structname>pg_stat_lock</structname></link> for details. + </entry> + </row> + <row> <entry><structname>pg_stat_replication_slots</structname><indexterm><primary>pg_stat_replication_slots</primary></indexterm></entry> <entry>One row per replication slot, showing statistics about the @@ -3283,6 +3292,104 @@ description | Waiting for a newly initialized WAL file to reach durable storage </sect2> + + <sect2 id="monitoring-pg-stat-lock-view"> + <title><structname>pg_stat_lock</structname></title> + + <indexterm> + <primary>pg_stat_lock</primary> + </indexterm> + + <para> + The <structname>pg_stat_lock</structname> view will contain one row for each + lock type, showing cluster-wide locks statistics. + </para> + + <table id="pg-stat-lock-view" xreflabel="pg_stat_lock"> + <title><structname>pg_stat_lock</structname> View</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + Column Type + </para> + <para> + Description + </para> + </entry> + </row> + </thead> + <tbody> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>locktype</structfield> <type>text</type> + </para> + <para> + Type of the lockable object. See <link linkend="view-pg-locks"> + <structname>pg_locks</structname></link> for details. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>waits</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type had to wait because of a + conflicting lock. Only incremented when <xref linkend="guc-log-lock-waits"/> + is enabled and the lock was successfully acquired after waiting longer + than <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>wait_time</structfield> <type>bigint</type> + </para> + <para> + Total time spent waiting for locks of this type, in milliseconds. + Only incremented when <xref linkend="guc-log-lock-waits"/> is enabled and + the lock was successfully acquired after waiting longer than + <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>fastpath_exceeded</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type could not be acquired via fast path + because the fast path slot limit was exceeded. You may want to increase + <xref linkend="guc-max-locks-per-transaction"/> if you feel this counter + is too high. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>stats_reset</structfield> <type>timestamp with time zone</type> + </para> + <para> + Time at which these statistics were last reset. + </para> + </entry> + </row> + </tbody> + </tgroup> + </table> + </sect2> + <sect2 id="monitoring-pg-stat-bgwriter-view"> <title><structname>pg_stat_bgwriter</structname></title> @@ -5372,6 +5479,12 @@ description | Waiting for a newly initialized WAL file to reach durable storage <structname>pg_stat_io</structname> view. </para> </listitem> + <listitem> + <para> + <literal>lock</literal>: Reset all the counters shown in the + <structname>pg_stat_lock</structname> view. + </para> + </listitem> <listitem> <para> <literal>recovery_prefetch</literal>: Reset all the counters shown in diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index f1ed7b58f13..e54018004db 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -985,6 +985,15 @@ CREATE VIEW pg_stat_slru AS s.stats_reset FROM pg_stat_get_slru() s; +CREATE VIEW pg_stat_lock AS + SELECT + l.locktype, + l.waits, + l.wait_time, + l.fastpath_exceeded, + l.stats_reset + FROM pg_stat_get_lock() l; + CREATE VIEW pg_stat_wal_receiver AS SELECT s.pid, diff --git a/src/backend/utils/activity/pgstat_lock.c b/src/backend/utils/activity/pgstat_lock.c index 9ec61f2b2ec..eccb12b0b68 100644 --- a/src/backend/utils/activity/pgstat_lock.c +++ b/src/backend/utils/activity/pgstat_lock.c @@ -21,6 +21,14 @@ static PgStat_PendingLock PendingLockStats; static bool have_lockstats = false; +PgStat_Lock * +pgstat_fetch_stat_lock(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_LOCK); + + return &pgStatLocal.snapshot.lock; +} + /* * Simpler wrapper of pgstat_lock_flush_cb() */ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 5f907335990..9185a8e6b83 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1741,6 +1741,42 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) wal_stats->stat_reset_timestamp)); } +Datum +pg_stat_get_lock(PG_FUNCTION_ARGS) +{ +#define PG_STAT_LOCK_COLS 5 + ReturnSetInfo *rsinfo; + PgStat_Lock *lock_stats; + + InitMaterializedSRF(fcinfo, 0); + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + lock_stats = pgstat_fetch_stat_lock(); + + for (int lcktype = 0; lcktype <= LOCKTAG_LAST_TYPE; lcktype++) + { + const char *locktypename; + Datum values[PG_STAT_LOCK_COLS] = {0}; + bool nulls[PG_STAT_LOCK_COLS] = {0}; + PgStat_LockEntry *lck_stats = &lock_stats->stats[lcktype]; + int i = 0; + + locktypename = LockTagTypeNames[lcktype]; + + values[i++] = CStringGetTextDatum(locktypename); + values[i++] = Int64GetDatum(lck_stats->waits); + values[i++] = Int64GetDatum(lck_stats->wait_time); + values[i++] = Int64GetDatum(lck_stats->fastpath_exceeded); + values[i] = TimestampTzGetDatum(lock_stats->stat_reset_timestamp); + + Assert(i + 1 == PG_STAT_LOCK_COLS); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} + /* * Returns statistics of SLRU caches. */ @@ -1925,6 +1961,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER); pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); pgstat_reset_of_kind(PGSTAT_KIND_IO); + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); @@ -1942,6 +1979,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); else if (strcmp(target, "io") == 0) pgstat_reset_of_kind(PGSTAT_KIND_IO); + else if (strcmp(target, "lock") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); else if (strcmp(target, "recovery_prefetch") == 0) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index fc8d82665b8..3e2c43e9d1b 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6041,6 +6041,15 @@ proargnames => '{backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}', prosrc => 'pg_stat_get_io' }, +{ oid => '9375', descr => 'statistics: per lock type statistics', + proname => 'pg_stat_get_lock', prorows => '10', proretset => 't', + provolatile => 'v', proparallel => 'r', prorettype => 'record', + proargtypes => '', + proallargtypes => '{text,int8,int8,int8,timestamptz}', + proargmodes => '{o,o,o,o,o}', + proargnames => '{locktype,waits,wait_time,fastpath_exceeded,stats_reset}', + prosrc => 'pg_stat_get_lock' }, + { oid => '6386', descr => 'statistics: backend IO statistics', proname => 'pg_stat_get_backend_io', prorows => '5', proretset => 't', provolatile => 'v', proparallel => 'r', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 4a28ea99705..06e2638e788 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -643,6 +643,7 @@ extern bool pgstat_tracks_io_op(BackendType bktype, IOObject io_object, extern void pgstat_lock_flush(bool nowait); extern void pgstat_count_lock_fastpath_exceeded(uint8 locktag_type); extern void pgstat_count_lock_waits(uint8 locktag_type, long msecs); +extern PgStat_Lock *pgstat_fetch_stat_lock(void); /* * Functions in pgstat_database.c diff --git a/src/test/isolation/expected/lock-stats.out b/src/test/isolation/expected/lock-stats.out new file mode 100644 index 00000000000..fa9e141dc20 --- /dev/null +++ b/src/test/isolation/expected/lock-stats.out @@ -0,0 +1,190 @@ +Parsed test spec with 2 sessions + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.05); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.05); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'transactionid'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); <waiting ...> +step s1_sleep: SELECT pg_sleep(0.05); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'advisory'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_unset_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_unset_log_lock_waits: SET log_lock_waits = off; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.05); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +f |f +(1 row) + diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule index 4e466580cd4..2cc86849c9a 100644 --- a/src/test/isolation/isolation_schedule +++ b/src/test/isolation/isolation_schedule @@ -43,6 +43,7 @@ test: eval-plan-qual-trigger test: inplace-inval test: intra-grant-inplace test: intra-grant-inplace-db +test: lock-stats test: lock-update-delete test: lock-update-traversal test: inherit-temp diff --git a/src/test/isolation/specs/lock-stats.spec b/src/test/isolation/specs/lock-stats.spec new file mode 100644 index 00000000000..2c5c91791e9 --- /dev/null +++ b/src/test/isolation/specs/lock-stats.spec @@ -0,0 +1,118 @@ +setup +{ + CREATE TABLE test_stat_tab(key text not null, value int); + INSERT INTO test_stat_tab(key, value) VALUES('k0', 1); + SELECT pg_stat_force_next_flush(); +} + +teardown +{ + DROP TABLE IF EXISTS test_stat_tab; +} + +session s1 +setup { SET stats_fetch_consistency = 'none'; } +step s1_begin { BEGIN; } +step s1_commit { COMMIT; } +step s1_table_insert { INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1);} +step s1_table_update_k1 { UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1';} +step s1_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s1_set_log_lock_waits { SET log_lock_waits = on; } +step s1_reset_stat_lock { SELECT pg_stat_reset_shared('lock'); } +step s1_sleep { SELECT pg_sleep(0.05); } +step s1_lock_relation { LOCK TABLE test_stat_tab; } +step s1_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s1_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } + +session s2 +setup { SET stats_fetch_consistency = 'none'; } +step s2_begin { BEGIN; } +step s2_commit { COMMIT; } +step s2_ff { SELECT pg_stat_force_next_flush(); } +step s2_table_update_k1 { UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1';} +step s2_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s2_set_log_lock_waits { SET log_lock_waits = on; } +step s2_unset_log_lock_waits { SET log_lock_waits = off; } +step s2_report_stat_lock_relation { SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'relation'; } +step s2_report_stat_lock_transactionid { SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'transactionid'; } +step s2_report_stat_lock_advisory { SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'advisory'; } +step s2_lock_relation { LOCK TABLE test_stat_tab; } +step s2_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s2_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } + +###################### +# Lock stats tests +###################### + +# relation lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation + +# transaction lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_table_insert + s1_begin + s1_table_update_k1 + s2_begin + s2_ff + s2_table_update_k1 + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_transactionid + +# advisory lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_lock_advisory_lock + s2_begin + s2_ff + s2_lock_advisory_lock + s1_sleep + s1_lock_advisory_unlock + s2_lock_advisory_unlock + s2_commit + s2_report_stat_lock_advisory + +# Ensure log_lock_waits behaves correctly + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_unset_log_lock_waits + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 32bea58db2c..2b3cf6d8569 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1952,6 +1952,12 @@ pg_stat_io| SELECT backend_type, fsync_time, stats_reset FROM pg_stat_get_io() b(backend_type, object, context, reads, read_bytes, read_time, writes, write_bytes, write_time, writebacks, writeback_time, extends, extend_bytes, extend_time, hits, evictions, reuses, fsyncs, fsync_time, stats_reset); +pg_stat_lock| SELECT locktype, + waits, + wait_time, + fastpath_exceeded, + stats_reset + FROM pg_stat_get_lock() l(locktype, waits, wait_time, fastpath_exceeded, stats_reset); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index b99462bf946..ea7f7846895 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -1958,4 +1958,52 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); (1 row) DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); +SELECT pg_stat_reset_shared('lock'); + pg_stat_reset_shared +---------------------- + +(1 row) + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + count +------- + 0 +(1 row) + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + ?column? +---------- + t +(1 row) + +DROP TABLE part_test; -- End of Stats Test diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 941222cf0be..65d8968c83e 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -964,4 +964,40 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); + +SELECT pg_stat_reset_shared('lock'); + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; + +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset + +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + +DROP TABLE part_test; + -- End of Stats Test -- 2.34.1 --NJ5Y8xm2S5PE3Q71-- ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v11 3/3] Add the pg_stat_lock view @ 2025-07-31 09:35 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Bertrand Drouvot @ 2025-07-31 09:35 UTC (permalink / raw) This new view reports lock statistics. Note that it does not omit combinations which do not make sense (as pg_locks does). Also wait_time is reported as bigint as the deadlock_timeout default value is 1s. This commit also adds documentation and a few tests. XXX: Bump catversion Author: Bertrand Drouvot <[email protected]> Reviewed-by: Andres Freund <[email protected]> Discussion: https://postgr.es/m/aIyNxBWFCybgBZBS%40ip-10-97-1-34.eu-west-3.compute.internal --- doc/src/sgml/monitoring.sgml | 111 ++++++++++++ src/backend/catalog/system_views.sql | 9 + src/backend/utils/activity/pgstat_lock.c | 8 + src/backend/utils/adt/pgstatfuncs.c | 39 +++++ src/include/catalog/pg_proc.dat | 9 + src/include/pgstat.h | 1 + src/test/isolation/expected/lock-stats.out | 190 +++++++++++++++++++++ src/test/isolation/isolation_schedule | 1 + src/test/isolation/specs/lock-stats.spec | 125 ++++++++++++++ src/test/regress/expected/rules.out | 6 + src/test/regress/expected/stats.out | 48 ++++++ src/test/regress/sql/stats.sql | 36 ++++ 12 files changed, 583 insertions(+) 19.9% doc/src/sgml/ 6.4% src/backend/utils/adt/ 35.1% src/test/isolation/expected/ 20.8% src/test/isolation/specs/ 7.4% src/test/regress/expected/ 5.2% src/test/regress/sql/ 4.8% src/ diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 462019a972c..d590ecad541 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -509,6 +509,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser </entry> </row> + <row> + <entry><structname>pg_stat_lock</structname><indexterm><primary>pg_stat_lock</primary></indexterm></entry> + <entry> + One row for each lock type, containing cluster-wide locks statistics. + See <link linkend="monitoring-pg-stat-lock-view"> + <structname>pg_stat_lock</structname></link> for details. + </entry> + </row> + <row> <entry><structname>pg_stat_replication_slots</structname><indexterm><primary>pg_stat_replication_slots</primary></indexterm></entry> <entry>One row per replication slot, showing statistics about the @@ -3283,6 +3292,102 @@ description | Waiting for a newly initialized WAL file to reach durable storage </sect2> + + <sect2 id="monitoring-pg-stat-lock-view"> + <title><structname>pg_stat_lock</structname></title> + + <indexterm> + <primary>pg_stat_lock</primary> + </indexterm> + + <para> + The <structname>pg_stat_lock</structname> view will contain one row for each + lock type, showing cluster-wide locks statistics. + </para> + + <table id="pg-stat-lock-view" xreflabel="pg_stat_lock"> + <title><structname>pg_stat_lock</structname> View</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + Column Type + </para> + <para> + Description + </para> + </entry> + </row> + </thead> + <tbody> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>locktype</structfield> <type>text</type> + </para> + <para> + Type of the lockable object. See <link linkend="view-pg-locks"> + <structname>pg_locks</structname></link> for details. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>waits</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type had to wait because of a + conflicting lock. Only incremented when the lock was successfully + acquired after waiting longer than <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>wait_time</structfield> <type>bigint</type> + </para> + <para> + Total time spent waiting for locks of this type, in milliseconds. + Only incremented when the lock was successfully acquired after waiting + longer than <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>fastpath_exceeded</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type could not be acquired via fast path + because the fast path slot limit was exceeded. You may want to increase + <xref linkend="guc-max-locks-per-transaction"/> if you feel this counter + is too high. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>stats_reset</structfield> <type>timestamp with time zone</type> + </para> + <para> + Time at which these statistics were last reset. + </para> + </entry> + </row> + </tbody> + </tgroup> + </table> + </sect2> + <sect2 id="monitoring-pg-stat-bgwriter-view"> <title><structname>pg_stat_bgwriter</structname></title> @@ -5372,6 +5477,12 @@ description | Waiting for a newly initialized WAL file to reach durable storage <structname>pg_stat_io</structname> view. </para> </listitem> + <listitem> + <para> + <literal>lock</literal>: Reset all the counters shown in the + <structname>pg_stat_lock</structname> view. + </para> + </listitem> <listitem> <para> <literal>recovery_prefetch</literal>: Reset all the counters shown in diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index f1ed7b58f13..e54018004db 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -985,6 +985,15 @@ CREATE VIEW pg_stat_slru AS s.stats_reset FROM pg_stat_get_slru() s; +CREATE VIEW pg_stat_lock AS + SELECT + l.locktype, + l.waits, + l.wait_time, + l.fastpath_exceeded, + l.stats_reset + FROM pg_stat_get_lock() l; + CREATE VIEW pg_stat_wal_receiver AS SELECT s.pid, diff --git a/src/backend/utils/activity/pgstat_lock.c b/src/backend/utils/activity/pgstat_lock.c index fe330eb99b1..76749e4724d 100644 --- a/src/backend/utils/activity/pgstat_lock.c +++ b/src/backend/utils/activity/pgstat_lock.c @@ -21,6 +21,14 @@ static PgStat_PendingLock PendingLockStats; static bool have_lockstats = false; +PgStat_Lock * +pgstat_fetch_stat_lock(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_LOCK); + + return &pgStatLocal.snapshot.lock; +} + /* * Simpler wrapper of pgstat_lock_flush_cb() */ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 5f907335990..9185a8e6b83 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1741,6 +1741,42 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) wal_stats->stat_reset_timestamp)); } +Datum +pg_stat_get_lock(PG_FUNCTION_ARGS) +{ +#define PG_STAT_LOCK_COLS 5 + ReturnSetInfo *rsinfo; + PgStat_Lock *lock_stats; + + InitMaterializedSRF(fcinfo, 0); + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + lock_stats = pgstat_fetch_stat_lock(); + + for (int lcktype = 0; lcktype <= LOCKTAG_LAST_TYPE; lcktype++) + { + const char *locktypename; + Datum values[PG_STAT_LOCK_COLS] = {0}; + bool nulls[PG_STAT_LOCK_COLS] = {0}; + PgStat_LockEntry *lck_stats = &lock_stats->stats[lcktype]; + int i = 0; + + locktypename = LockTagTypeNames[lcktype]; + + values[i++] = CStringGetTextDatum(locktypename); + values[i++] = Int64GetDatum(lck_stats->waits); + values[i++] = Int64GetDatum(lck_stats->wait_time); + values[i++] = Int64GetDatum(lck_stats->fastpath_exceeded); + values[i] = TimestampTzGetDatum(lock_stats->stat_reset_timestamp); + + Assert(i + 1 == PG_STAT_LOCK_COLS); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} + /* * Returns statistics of SLRU caches. */ @@ -1925,6 +1961,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER); pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); pgstat_reset_of_kind(PGSTAT_KIND_IO); + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); @@ -1942,6 +1979,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); else if (strcmp(target, "io") == 0) pgstat_reset_of_kind(PGSTAT_KIND_IO); + else if (strcmp(target, "lock") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); else if (strcmp(target, "recovery_prefetch") == 0) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index fc8d82665b8..3e2c43e9d1b 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6041,6 +6041,15 @@ proargnames => '{backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}', prosrc => 'pg_stat_get_io' }, +{ oid => '9375', descr => 'statistics: per lock type statistics', + proname => 'pg_stat_get_lock', prorows => '10', proretset => 't', + provolatile => 'v', proparallel => 'r', prorettype => 'record', + proargtypes => '', + proallargtypes => '{text,int8,int8,int8,timestamptz}', + proargmodes => '{o,o,o,o,o}', + proargnames => '{locktype,waits,wait_time,fastpath_exceeded,stats_reset}', + prosrc => 'pg_stat_get_lock' }, + { oid => '6386', descr => 'statistics: backend IO statistics', proname => 'pg_stat_get_backend_io', prorows => '5', proretset => 't', provolatile => 'v', proparallel => 'r', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 553106025da..dadf8b1c1ed 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -643,6 +643,7 @@ extern bool pgstat_tracks_io_op(BackendType bktype, IOObject io_object, extern void pgstat_lock_flush(bool nowait); extern void pgstat_count_lock_fastpath_exceeded(uint8 locktag_type); extern void pgstat_count_lock_waits(uint8 locktag_type, long msecs); +extern PgStat_Lock *pgstat_fetch_stat_lock(void); /* * Functions in pgstat_database.c diff --git a/src/test/isolation/expected/lock-stats.out b/src/test/isolation/expected/lock-stats.out new file mode 100644 index 00000000000..556c210a28b --- /dev/null +++ b/src/test/isolation/expected/lock-stats.out @@ -0,0 +1,190 @@ +Parsed test spec with 2 sessions + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.05); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.05); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'transactionid'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_set_log_lock_waits s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); <waiting ...> +step s1_sleep: SELECT pg_sleep(0.05); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'advisory'; +?column?|?column? +--------+-------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_log_lock_waits s2_set_deadlock_timeout s2_unset_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_log_lock_waits: SET log_lock_waits = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_unset_log_lock_waits: SET log_lock_waits = off; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.05); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +t |t +(1 row) + diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule index 4e466580cd4..2cc86849c9a 100644 --- a/src/test/isolation/isolation_schedule +++ b/src/test/isolation/isolation_schedule @@ -43,6 +43,7 @@ test: eval-plan-qual-trigger test: inplace-inval test: intra-grant-inplace test: intra-grant-inplace-db +test: lock-stats test: lock-update-delete test: lock-update-traversal test: inherit-temp diff --git a/src/test/isolation/specs/lock-stats.spec b/src/test/isolation/specs/lock-stats.spec new file mode 100644 index 00000000000..e4e66a9fb4d --- /dev/null +++ b/src/test/isolation/specs/lock-stats.spec @@ -0,0 +1,125 @@ +# Test for the lock statistics +# +# This test creates multiple locking situations when a session (s2) has to +# wait on a lock for longer than the deadlock timeout. The first permutations +# each test a dedicated lock type. The last permutation ensures that +# log_lock_waits has no impact on the statistics counters. + +setup +{ + CREATE TABLE test_stat_tab(key text not null, value int); + INSERT INTO test_stat_tab(key, value) VALUES('k0', 1); + SELECT pg_stat_force_next_flush(); +} + +teardown +{ + DROP TABLE IF EXISTS test_stat_tab; +} + +session s1 +setup { SET stats_fetch_consistency = 'none'; } +step s1_begin { BEGIN; } +step s1_commit { COMMIT; } +step s1_table_insert { INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1);} +step s1_table_update_k1 { UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1';} +step s1_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s1_set_log_lock_waits { SET log_lock_waits = on; } +step s1_reset_stat_lock { SELECT pg_stat_reset_shared('lock'); } +step s1_sleep { SELECT pg_sleep(0.05); } +step s1_lock_relation { LOCK TABLE test_stat_tab; } +step s1_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s1_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } + +session s2 +setup { SET stats_fetch_consistency = 'none'; } +step s2_begin { BEGIN; } +step s2_commit { COMMIT; } +step s2_ff { SELECT pg_stat_force_next_flush(); } +step s2_table_update_k1 { UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1';} +step s2_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s2_set_log_lock_waits { SET log_lock_waits = on; } +step s2_unset_log_lock_waits { SET log_lock_waits = off; } +step s2_report_stat_lock_relation { SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'relation'; } +step s2_report_stat_lock_transactionid { SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'transactionid'; } +step s2_report_stat_lock_advisory { SELECT waits > 0, wait_time > 50 FROM pg_stat_lock WHERE locktype = 'advisory'; } +step s2_lock_relation { LOCK TABLE test_stat_tab; } +step s2_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s2_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } + +###################### +# Lock stats tests +###################### + +# relation lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation + +# transaction lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_table_insert + s1_begin + s1_table_update_k1 + s2_begin + s2_ff + s2_table_update_k1 + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_transactionid + +# advisory lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_lock_advisory_lock + s2_begin + s2_ff + s2_lock_advisory_lock + s1_sleep + s1_lock_advisory_unlock + s2_lock_advisory_unlock + s2_commit + s2_report_stat_lock_advisory + +# Ensure log_lock_waits has no impact + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_log_lock_waits + s2_set_deadlock_timeout + s2_unset_log_lock_waits + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 32bea58db2c..2b3cf6d8569 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1952,6 +1952,12 @@ pg_stat_io| SELECT backend_type, fsync_time, stats_reset FROM pg_stat_get_io() b(backend_type, object, context, reads, read_bytes, read_time, writes, write_bytes, write_time, writebacks, writeback_time, extends, extend_bytes, extend_time, hits, evictions, reuses, fsyncs, fsync_time, stats_reset); +pg_stat_lock| SELECT locktype, + waits, + wait_time, + fastpath_exceeded, + stats_reset + FROM pg_stat_get_lock() l(locktype, waits, wait_time, fastpath_exceeded, stats_reset); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index b99462bf946..ea7f7846895 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -1958,4 +1958,52 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); (1 row) DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); +SELECT pg_stat_reset_shared('lock'); + pg_stat_reset_shared +---------------------- + +(1 row) + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + count +------- + 0 +(1 row) + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + ?column? +---------- + t +(1 row) + +DROP TABLE part_test; -- End of Stats Test diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 941222cf0be..65d8968c83e 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -964,4 +964,40 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); + +SELECT pg_stat_reset_shared('lock'); + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; + +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset + +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + +DROP TABLE part_test; + -- End of Stats Test -- 2.34.1 --YVZ2rdHTqHRFZ4HX-- ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v1 2/2] Add the pg_stat_lock view @ 2025-07-31 09:35 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Bertrand Drouvot @ 2025-07-31 09:35 UTC (permalink / raw) This new view reports lock statistics. This commit also adds documentation and a few tests. XXX: Bump catversion --- doc/src/sgml/monitoring.sgml | 151 ++++++++++++++++++ src/backend/catalog/system_views.sql | 12 ++ src/backend/utils/activity/pgstat_lock.c | 8 + src/backend/utils/adt/pgstatfuncs.c | 39 +++++ src/include/catalog/pg_proc.dat | 9 ++ src/include/pgstat.h | 1 + src/test/isolation/expected/deadlock-hard.out | 20 ++- src/test/isolation/specs/deadlock-hard.spec | 5 +- src/test/regress/expected/advisory_lock.out | 18 +++ src/test/regress/expected/rules.out | 9 ++ src/test/regress/sql/advisory_lock.sql | 4 + 11 files changed, 274 insertions(+), 2 deletions(-) 51.5% doc/src/sgml/ 3.3% src/backend/catalog/ 14.3% src/backend/utils/adt/ 5.7% src/include/catalog/ 8.4% src/test/isolation/expected/ 5.9% src/test/isolation/specs/ 6.7% src/test/regress/expected/ 3.8% src/ diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 823afe1b30b..0d18124f239 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -493,6 +493,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser </entry> </row> + <row> + <entry><structname>pg_stat_lock</structname><indexterm><primary>pg_stat_lock</primary></indexterm></entry> + <entry> + One row for each lock type, containing cluster-wide locks statistics. + See <link linkend="monitoring-pg-stat-lock-view"> + <structname>pg_stat_lock</structname></link> for details. + </entry> + </row> + <row> <entry><structname>pg_stat_replication_slots</structname><indexterm><primary>pg_stat_replication_slots</primary></indexterm></entry> <entry>One row per replication slot, showing statistics about the @@ -3027,6 +3036,142 @@ description | Waiting for a newly initialized WAL file to reach durable storage </sect2> + + <sect2 id="monitoring-pg-stat-lock-view"> + <title><structname>pg_stat_lock</structname></title> + + <indexterm> + <primary>pg_stat_lock</primary> + </indexterm> + + <para> + The <structname>pg_stat_lock</structname> view will contain one row for each + lock type, showing cluster-wide locks statistics. + </para> + + <table id="pg-stat-lock-view" xreflabel="pg_stat_lock"> + <title><structname>pg_stat_lock</structname> View</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + Column Type + </para> + <para> + Description + </para> + </entry> + </row> + </thead> + <tbody> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>locktype</structfield> <type>text</type> + </para> + <para> + Type of the lockable object: + <literal>relation</literal>, + <literal>extend</literal>, + <literal>frozenid</literal>, + <literal>page</literal>, + <literal>tuple</literal>, + <literal>transactionid</literal>, + <literal>virtualxid</literal>, + <literal>spectoken</literal>, + <literal>object</literal>, + <literal>userlock</literal>, + <literal>advisory</literal>, or + <literal>applytransaction</literal>. + (See also <xref linkend="wait-event-lock-table"/>.) + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>requests</structfield> <type>bigint</type> + </para> + <para> + Number of requests for this lock type. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>waits</structfield> <type>bigint</type> + </para> + <para> + Number of times requests for this lock type had to wait. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>timeouts</structfield> <type>bigint</type> + </para> + <para> + Number of times requests for this lock type had to wait longer + than <varname>lock_timeout</varname>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>deadlock_timeouts</structfield> <type>bigint</type> + </para> + <para> + Number of times requests for this lock type had to wait longer + than <varname>deadlock_timeout</varname>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>deadlocks</structfield> <type>bigint</type> + </para> + <para> + Number of times a deadlock occurred on this lock type. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>fastpath</structfield> <type>bigint</type> + </para> + <para> + Number of times this lock type was taken via fast path. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>stats_reset</structfield> <type>timestamp with time zone</type> + </para> + <para> + Time at which these statistics were last reset. + </para> + </entry> + </row> + </tbody> + </tgroup> + </table> + </sect2> + <sect2 id="monitoring-pg-stat-bgwriter-view"> <title><structname>pg_stat_bgwriter</structname></title> @@ -5044,6 +5189,12 @@ description | Waiting for a newly initialized WAL file to reach durable storage <structname>pg_stat_io</structname> view. </para> </listitem> + <listitem> + <para> + <literal>lock</literal>: Reset all the counters shown in the + <structname>pg_stat_lock</structname> view. + </para> + </listitem> <listitem> <para> <literal>recovery_prefetch</literal>: Reset all the counters shown in diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index f6eca09ee15..d493a00c544 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -950,6 +950,18 @@ CREATE VIEW pg_stat_slru AS s.stats_reset FROM pg_stat_get_slru() s; +CREATE VIEW pg_stat_lock AS + SELECT + l.locktype, + l.requests, + l.waits, + l.timeouts, + l.deadlock_timeouts, + l.deadlocks, + l.fastpath, + l.stats_reset + FROM pg_stat_get_lock() l; + CREATE VIEW pg_stat_wal_receiver AS SELECT s.pid, diff --git a/src/backend/utils/activity/pgstat_lock.c b/src/backend/utils/activity/pgstat_lock.c index fb4ed5c7362..73bdeb5ff66 100644 --- a/src/backend/utils/activity/pgstat_lock.c +++ b/src/backend/utils/activity/pgstat_lock.c @@ -21,6 +21,14 @@ static PgStat_PendingLock PendingLockStats; static bool have_lockstats = false; +PgStat_Lock * +pgstat_fetch_stat_lock(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_LOCK); + + return &pgStatLocal.snapshot.lock; +} + /* * Simpler wrapper of pgstat_lock_flush_cb() */ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 1c12ddbae49..5e63f2d2a38 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1696,6 +1696,42 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) wal_stats->stat_reset_timestamp)); } +Datum +pg_stat_get_lock(PG_FUNCTION_ARGS) +{ +#define PG_STAT_LOCK_COLS 8 + ReturnSetInfo *rsinfo; + PgStat_Lock *lock_stats; + + InitMaterializedSRF(fcinfo, 0); + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + lock_stats = pgstat_fetch_stat_lock(); + + for (int lcktype = 0; lcktype <= LOCKTAG_LAST_TYPE; lcktype++) + { + const char *locktypename; + Datum values[PG_STAT_LOCK_COLS] = {0}; + bool nulls[PG_STAT_LOCK_COLS] = {0}; + PgStat_LockEntry *lck_stats = &lock_stats->stats[lcktype]; + + locktypename = LockTagTypeNames[lcktype]; + + values[0] = CStringGetTextDatum(locktypename); + values[1] = Int64GetDatum(lck_stats->requests); + values[2] = Int64GetDatum(lck_stats->waits); + values[3] = Int64GetDatum(lck_stats->timeouts); + values[4] = Int64GetDatum(lck_stats->deadlock_timeouts); + values[5] = Int64GetDatum(lck_stats->deadlocks); + values[6] = Int64GetDatum(lck_stats->fastpath); + values[7] = TimestampTzGetDatum(lock_stats->stat_reset_timestamp); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} + /* * Returns statistics of SLRU caches. */ @@ -1880,6 +1916,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER); pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); pgstat_reset_of_kind(PGSTAT_KIND_IO); + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); @@ -1897,6 +1934,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); else if (strcmp(target, "io") == 0) pgstat_reset_of_kind(PGSTAT_KIND_IO); + else if (strcmp(target, "lock") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); else if (strcmp(target, "recovery_prefetch") == 0) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 3ee8fed7e53..c5faff30317 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6001,6 +6001,15 @@ proargnames => '{backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}', prosrc => 'pg_stat_get_io' }, +{ oid => '9375', descr => 'statistics: per lock type statistics', + proname => 'pg_stat_get_lock', prorows => '10', proretset => 't', + provolatile => 'v', proparallel => 'r', prorettype => 'record', + proargtypes => '', + proallargtypes => '{text,int8,int8,int8,int8,int8,int8,timestamptz}', + proargmodes => '{o,o,o,o,o,o,o,o}', + proargnames => '{locktype,requests,waits,timeouts,deadlock_timeouts,deadlocks,fastpath,stats_reset}', + prosrc => 'pg_stat_get_lock' }, + { oid => '6386', descr => 'statistics: backend IO statistics', proname => 'pg_stat_get_backend_io', prorows => '5', proretset => 't', provolatile => 'v', proparallel => 'r', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 7893f7311ae..e653bce4aab 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -636,6 +636,7 @@ extern void pgstat_count_lock_timeouts(uint8 locktag_type); extern void pgstat_count_lock_deadlock_timeouts(uint8 locktag_type); extern void pgstat_count_lock_deadlocks(uint8 locktag_type); extern void pgstat_count_lock_fastpath(uint8 locktag_type); +extern PgStat_Lock *pgstat_fetch_stat_lock(void); /* * Functions in pgstat_database.c diff --git a/src/test/isolation/expected/deadlock-hard.out b/src/test/isolation/expected/deadlock-hard.out index 460653f2b86..ff448da5299 100644 --- a/src/test/isolation/expected/deadlock-hard.out +++ b/src/test/isolation/expected/deadlock-hard.out @@ -1,6 +1,12 @@ Parsed test spec with 8 sessions -starting permutation: s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8 s8a1 s8c s7c s6c s5c s4c s3c s2c s1c +starting permutation: s1rl s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8 s8a1 s8c s8f s7c s6c s5c s4c s3c s2c s1c s1sl +step s1rl: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + step s1a1: LOCK TABLE a1; step s2a2: LOCK TABLE a2; step s3a3: LOCK TABLE a3; @@ -21,6 +27,12 @@ step s8a1: <... completed> ERROR: deadlock detected step s7a8: <... completed> step s8c: COMMIT; +step s8f: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + step s7c: COMMIT; step s6a7: <... completed> step s6c: COMMIT; @@ -34,3 +46,9 @@ step s2a3: <... completed> step s2c: COMMIT; step s1a2: <... completed> step s1c: COMMIT; +step s1sl: SELECT deadlocks > 0, deadlock_timeouts > 0 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +t |t +(1 row) + diff --git a/src/test/isolation/specs/deadlock-hard.spec b/src/test/isolation/specs/deadlock-hard.spec index 60bedca237a..6e8330662b4 100644 --- a/src/test/isolation/specs/deadlock-hard.spec +++ b/src/test/isolation/specs/deadlock-hard.spec @@ -25,6 +25,8 @@ setup { BEGIN; SET deadlock_timeout = '100s'; } step s1a1 { LOCK TABLE a1; } step s1a2 { LOCK TABLE a2; } step s1c { COMMIT; } +step s1sl { SELECT deadlocks > 0, deadlock_timeouts > 0 FROM pg_stat_lock WHERE locktype = 'relation'; } +step s1rl { SELECT pg_stat_reset_shared('lock'); } session s2 setup { BEGIN; SET deadlock_timeout = '100s'; } @@ -67,6 +69,7 @@ setup { BEGIN; SET deadlock_timeout = '10ms'; } step s8a8 { LOCK TABLE a8; } step s8a1 { LOCK TABLE a1; } step s8c { COMMIT; } +step s8f { SELECT pg_stat_force_next_flush(); } # Note: when s8a1 detects the deadlock and fails, s7a8 is released, making # it timing-dependent which query completion is received first by the tester. @@ -76,4 +79,4 @@ step s8c { COMMIT; } # dummy blocking mark to s8a1 to ensure it will be reported as "waiting" # regardless of that. -permutation s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8(s8a1) s8a1(*) s8c s7c s6c s5c s4c s3c s2c s1c +permutation s1rl s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8(s8a1) s8a1(*) s8c s8f s7c s6c s5c s4c s3c s2c s1c s1sl diff --git a/src/test/regress/expected/advisory_lock.out b/src/test/regress/expected/advisory_lock.out index 02e07765ac2..fdaa1756ba4 100644 --- a/src/test/regress/expected/advisory_lock.out +++ b/src/test/regress/expected/advisory_lock.out @@ -2,6 +2,12 @@ -- ADVISORY LOCKS -- SELECT oid AS datoid FROM pg_database WHERE datname = current_database() \gset +SELECT pg_stat_reset_shared('lock'); + pg_stat_reset_shared +---------------------- + +(1 row) + BEGIN; SELECT pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2), @@ -48,6 +54,12 @@ WARNING: you don't own a lock of type ShareLock f | f | f | f (1 row) +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + -- automatically release xact locks at commit COMMIT; SELECT count(*) FROM pg_locks WHERE locktype = 'advisory' AND database = :datoid; @@ -56,6 +68,12 @@ SELECT count(*) FROM pg_locks WHERE locktype = 'advisory' AND database = :datoid 0 (1 row) +SELECT requests FROM pg_stat_lock WHERE locktype = 'advisory'; + requests +---------- + 4 +(1 row) + BEGIN; -- holding both session and xact locks on the same objects, xact first SELECT diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index dce8c672b40..c790164ea82 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1938,6 +1938,15 @@ pg_stat_io| SELECT backend_type, fsync_time, stats_reset FROM pg_stat_get_io() b(backend_type, object, context, reads, read_bytes, read_time, writes, write_bytes, write_time, writebacks, writeback_time, extends, extend_bytes, extend_time, hits, evictions, reuses, fsyncs, fsync_time, stats_reset); +pg_stat_lock| SELECT locktype, + requests, + waits, + timeouts, + deadlock_timeouts, + deadlocks, + fastpath, + stats_reset + FROM pg_stat_get_lock() l(locktype, requests, waits, timeouts, deadlock_timeouts, deadlocks, fastpath, stats_reset); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, diff --git a/src/test/regress/sql/advisory_lock.sql b/src/test/regress/sql/advisory_lock.sql index 8513ab8e98f..f1bff60fd37 100644 --- a/src/test/regress/sql/advisory_lock.sql +++ b/src/test/regress/sql/advisory_lock.sql @@ -4,6 +4,8 @@ SELECT oid AS datoid FROM pg_database WHERE datname = current_database() \gset +SELECT pg_stat_reset_shared('lock'); + BEGIN; SELECT @@ -26,12 +28,14 @@ SELECT pg_advisory_unlock(1), pg_advisory_unlock_shared(2), pg_advisory_unlock(1, 1), pg_advisory_unlock_shared(2, 2); +SELECT pg_stat_force_next_flush(); -- automatically release xact locks at commit COMMIT; SELECT count(*) FROM pg_locks WHERE locktype = 'advisory' AND database = :datoid; +SELECT requests FROM pg_stat_lock WHERE locktype = 'advisory'; BEGIN; -- 2.34.1 --Th7cMauVQntl/Hn1-- ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v2 2/2] Add the pg_stat_lock view @ 2025-07-31 09:35 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Bertrand Drouvot @ 2025-07-31 09:35 UTC (permalink / raw) This new view reports lock statistics. This commit also adds documentation and a few tests. XXX: Bump catversion --- doc/src/sgml/monitoring.sgml | 151 ++++++++++++++++++ src/backend/catalog/system_views.sql | 12 ++ src/backend/utils/activity/pgstat_lock.c | 8 + src/backend/utils/adt/pgstatfuncs.c | 39 +++++ src/include/catalog/pg_proc.dat | 9 ++ src/include/pgstat.h | 1 + src/test/isolation/expected/deadlock-hard.out | 20 ++- src/test/isolation/specs/deadlock-hard.spec | 5 +- src/test/regress/expected/advisory_lock.out | 18 +++ src/test/regress/expected/rules.out | 9 ++ src/test/regress/sql/advisory_lock.sql | 4 + 11 files changed, 274 insertions(+), 2 deletions(-) 51.5% doc/src/sgml/ 3.3% src/backend/catalog/ 14.3% src/backend/utils/adt/ 5.7% src/include/catalog/ 8.4% src/test/isolation/expected/ 5.9% src/test/isolation/specs/ 6.7% src/test/regress/expected/ 3.8% src/ diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 817fd9f4ca7..3c327093543 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -493,6 +493,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser </entry> </row> + <row> + <entry><structname>pg_stat_lock</structname><indexterm><primary>pg_stat_lock</primary></indexterm></entry> + <entry> + One row for each lock type, containing cluster-wide locks statistics. + See <link linkend="monitoring-pg-stat-lock-view"> + <structname>pg_stat_lock</structname></link> for details. + </entry> + </row> + <row> <entry><structname>pg_stat_replication_slots</structname><indexterm><primary>pg_stat_replication_slots</primary></indexterm></entry> <entry>One row per replication slot, showing statistics about the @@ -3087,6 +3096,142 @@ description | Waiting for a newly initialized WAL file to reach durable storage </sect2> + + <sect2 id="monitoring-pg-stat-lock-view"> + <title><structname>pg_stat_lock</structname></title> + + <indexterm> + <primary>pg_stat_lock</primary> + </indexterm> + + <para> + The <structname>pg_stat_lock</structname> view will contain one row for each + lock type, showing cluster-wide locks statistics. + </para> + + <table id="pg-stat-lock-view" xreflabel="pg_stat_lock"> + <title><structname>pg_stat_lock</structname> View</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + Column Type + </para> + <para> + Description + </para> + </entry> + </row> + </thead> + <tbody> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>locktype</structfield> <type>text</type> + </para> + <para> + Type of the lockable object: + <literal>relation</literal>, + <literal>extend</literal>, + <literal>frozenid</literal>, + <literal>page</literal>, + <literal>tuple</literal>, + <literal>transactionid</literal>, + <literal>virtualxid</literal>, + <literal>spectoken</literal>, + <literal>object</literal>, + <literal>userlock</literal>, + <literal>advisory</literal>, or + <literal>applytransaction</literal>. + (See also <xref linkend="wait-event-lock-table"/>.) + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>requests</structfield> <type>bigint</type> + </para> + <para> + Number of requests for this lock type. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>waits</structfield> <type>bigint</type> + </para> + <para> + Number of times requests for this lock type had to wait. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>timeouts</structfield> <type>bigint</type> + </para> + <para> + Number of times requests for this lock type had to wait longer + than <varname>lock_timeout</varname>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>deadlock_timeouts</structfield> <type>bigint</type> + </para> + <para> + Number of times requests for this lock type had to wait longer + than <varname>deadlock_timeout</varname>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>deadlocks</structfield> <type>bigint</type> + </para> + <para> + Number of times a deadlock occurred on this lock type. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>fastpath</structfield> <type>bigint</type> + </para> + <para> + Number of times this lock type was taken via fast path. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>stats_reset</structfield> <type>timestamp with time zone</type> + </para> + <para> + Time at which these statistics were last reset. + </para> + </entry> + </row> + </tbody> + </tgroup> + </table> + </sect2> + <sect2 id="monitoring-pg-stat-bgwriter-view"> <title><structname>pg_stat_bgwriter</structname></title> @@ -5158,6 +5303,12 @@ description | Waiting for a newly initialized WAL file to reach durable storage <structname>pg_stat_io</structname> view. </para> </listitem> + <listitem> + <para> + <literal>lock</literal>: Reset all the counters shown in the + <structname>pg_stat_lock</structname> view. + </para> + </listitem> <listitem> <para> <literal>recovery_prefetch</literal>: Reset all the counters shown in diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 0a0f95f6bb9..43969783069 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -964,6 +964,18 @@ CREATE VIEW pg_stat_slru AS s.stats_reset FROM pg_stat_get_slru() s; +CREATE VIEW pg_stat_lock AS + SELECT + l.locktype, + l.requests, + l.waits, + l.timeouts, + l.deadlock_timeouts, + l.deadlocks, + l.fastpath, + l.stats_reset + FROM pg_stat_get_lock() l; + CREATE VIEW pg_stat_wal_receiver AS SELECT s.pid, diff --git a/src/backend/utils/activity/pgstat_lock.c b/src/backend/utils/activity/pgstat_lock.c index fb4ed5c7362..73bdeb5ff66 100644 --- a/src/backend/utils/activity/pgstat_lock.c +++ b/src/backend/utils/activity/pgstat_lock.c @@ -21,6 +21,14 @@ static PgStat_PendingLock PendingLockStats; static bool have_lockstats = false; +PgStat_Lock * +pgstat_fetch_stat_lock(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_LOCK); + + return &pgStatLocal.snapshot.lock; +} + /* * Simpler wrapper of pgstat_lock_flush_cb() */ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index ef6fffe60b9..602228263a9 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1725,6 +1725,42 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) wal_stats->stat_reset_timestamp)); } +Datum +pg_stat_get_lock(PG_FUNCTION_ARGS) +{ +#define PG_STAT_LOCK_COLS 8 + ReturnSetInfo *rsinfo; + PgStat_Lock *lock_stats; + + InitMaterializedSRF(fcinfo, 0); + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + lock_stats = pgstat_fetch_stat_lock(); + + for (int lcktype = 0; lcktype <= LOCKTAG_LAST_TYPE; lcktype++) + { + const char *locktypename; + Datum values[PG_STAT_LOCK_COLS] = {0}; + bool nulls[PG_STAT_LOCK_COLS] = {0}; + PgStat_LockEntry *lck_stats = &lock_stats->stats[lcktype]; + + locktypename = LockTagTypeNames[lcktype]; + + values[0] = CStringGetTextDatum(locktypename); + values[1] = Int64GetDatum(lck_stats->requests); + values[2] = Int64GetDatum(lck_stats->waits); + values[3] = Int64GetDatum(lck_stats->timeouts); + values[4] = Int64GetDatum(lck_stats->deadlock_timeouts); + values[5] = Int64GetDatum(lck_stats->deadlocks); + values[6] = Int64GetDatum(lck_stats->fastpath); + values[7] = TimestampTzGetDatum(lock_stats->stat_reset_timestamp); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} + /* * Returns statistics of SLRU caches. */ @@ -1909,6 +1945,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER); pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); pgstat_reset_of_kind(PGSTAT_KIND_IO); + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); @@ -1926,6 +1963,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); else if (strcmp(target, "io") == 0) pgstat_reset_of_kind(PGSTAT_KIND_IO); + else if (strcmp(target, "lock") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); else if (strcmp(target, "recovery_prefetch") == 0) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index fd9448ec7b9..bb466f9e5dd 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6017,6 +6017,15 @@ proargnames => '{backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}', prosrc => 'pg_stat_get_io' }, +{ oid => '9375', descr => 'statistics: per lock type statistics', + proname => 'pg_stat_get_lock', prorows => '10', proretset => 't', + provolatile => 'v', proparallel => 'r', prorettype => 'record', + proargtypes => '', + proallargtypes => '{text,int8,int8,int8,int8,int8,int8,timestamptz}', + proargmodes => '{o,o,o,o,o,o,o,o}', + proargnames => '{locktype,requests,waits,timeouts,deadlock_timeouts,deadlocks,fastpath,stats_reset}', + prosrc => 'pg_stat_get_lock' }, + { oid => '6386', descr => 'statistics: backend IO statistics', proname => 'pg_stat_get_backend_io', prorows => '5', proretset => 't', provolatile => 'v', proparallel => 'r', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 913517ba612..38a9a7a9976 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -647,6 +647,7 @@ extern void pgstat_count_lock_timeouts(uint8 locktag_type); extern void pgstat_count_lock_deadlock_timeouts(uint8 locktag_type); extern void pgstat_count_lock_deadlocks(uint8 locktag_type); extern void pgstat_count_lock_fastpath(uint8 locktag_type); +extern PgStat_Lock *pgstat_fetch_stat_lock(void); /* * Functions in pgstat_database.c diff --git a/src/test/isolation/expected/deadlock-hard.out b/src/test/isolation/expected/deadlock-hard.out index 460653f2b86..ff448da5299 100644 --- a/src/test/isolation/expected/deadlock-hard.out +++ b/src/test/isolation/expected/deadlock-hard.out @@ -1,6 +1,12 @@ Parsed test spec with 8 sessions -starting permutation: s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8 s8a1 s8c s7c s6c s5c s4c s3c s2c s1c +starting permutation: s1rl s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8 s8a1 s8c s8f s7c s6c s5c s4c s3c s2c s1c s1sl +step s1rl: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + step s1a1: LOCK TABLE a1; step s2a2: LOCK TABLE a2; step s3a3: LOCK TABLE a3; @@ -21,6 +27,12 @@ step s8a1: <... completed> ERROR: deadlock detected step s7a8: <... completed> step s8c: COMMIT; +step s8f: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + step s7c: COMMIT; step s6a7: <... completed> step s6c: COMMIT; @@ -34,3 +46,9 @@ step s2a3: <... completed> step s2c: COMMIT; step s1a2: <... completed> step s1c: COMMIT; +step s1sl: SELECT deadlocks > 0, deadlock_timeouts > 0 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +t |t +(1 row) + diff --git a/src/test/isolation/specs/deadlock-hard.spec b/src/test/isolation/specs/deadlock-hard.spec index 60bedca237a..6e8330662b4 100644 --- a/src/test/isolation/specs/deadlock-hard.spec +++ b/src/test/isolation/specs/deadlock-hard.spec @@ -25,6 +25,8 @@ setup { BEGIN; SET deadlock_timeout = '100s'; } step s1a1 { LOCK TABLE a1; } step s1a2 { LOCK TABLE a2; } step s1c { COMMIT; } +step s1sl { SELECT deadlocks > 0, deadlock_timeouts > 0 FROM pg_stat_lock WHERE locktype = 'relation'; } +step s1rl { SELECT pg_stat_reset_shared('lock'); } session s2 setup { BEGIN; SET deadlock_timeout = '100s'; } @@ -67,6 +69,7 @@ setup { BEGIN; SET deadlock_timeout = '10ms'; } step s8a8 { LOCK TABLE a8; } step s8a1 { LOCK TABLE a1; } step s8c { COMMIT; } +step s8f { SELECT pg_stat_force_next_flush(); } # Note: when s8a1 detects the deadlock and fails, s7a8 is released, making # it timing-dependent which query completion is received first by the tester. @@ -76,4 +79,4 @@ step s8c { COMMIT; } # dummy blocking mark to s8a1 to ensure it will be reported as "waiting" # regardless of that. -permutation s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8(s8a1) s8a1(*) s8c s7c s6c s5c s4c s3c s2c s1c +permutation s1rl s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8(s8a1) s8a1(*) s8c s8f s7c s6c s5c s4c s3c s2c s1c s1sl diff --git a/src/test/regress/expected/advisory_lock.out b/src/test/regress/expected/advisory_lock.out index 02e07765ac2..fdaa1756ba4 100644 --- a/src/test/regress/expected/advisory_lock.out +++ b/src/test/regress/expected/advisory_lock.out @@ -2,6 +2,12 @@ -- ADVISORY LOCKS -- SELECT oid AS datoid FROM pg_database WHERE datname = current_database() \gset +SELECT pg_stat_reset_shared('lock'); + pg_stat_reset_shared +---------------------- + +(1 row) + BEGIN; SELECT pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2), @@ -48,6 +54,12 @@ WARNING: you don't own a lock of type ShareLock f | f | f | f (1 row) +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + -- automatically release xact locks at commit COMMIT; SELECT count(*) FROM pg_locks WHERE locktype = 'advisory' AND database = :datoid; @@ -56,6 +68,12 @@ SELECT count(*) FROM pg_locks WHERE locktype = 'advisory' AND database = :datoid 0 (1 row) +SELECT requests FROM pg_stat_lock WHERE locktype = 'advisory'; + requests +---------- + 4 +(1 row) + BEGIN; -- holding both session and xact locks on the same objects, xact first SELECT diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 4286c266e17..304d9f72ed5 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1949,6 +1949,15 @@ pg_stat_io| SELECT backend_type, fsync_time, stats_reset FROM pg_stat_get_io() b(backend_type, object, context, reads, read_bytes, read_time, writes, write_bytes, write_time, writebacks, writeback_time, extends, extend_bytes, extend_time, hits, evictions, reuses, fsyncs, fsync_time, stats_reset); +pg_stat_lock| SELECT locktype, + requests, + waits, + timeouts, + deadlock_timeouts, + deadlocks, + fastpath, + stats_reset + FROM pg_stat_get_lock() l(locktype, requests, waits, timeouts, deadlock_timeouts, deadlocks, fastpath, stats_reset); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, diff --git a/src/test/regress/sql/advisory_lock.sql b/src/test/regress/sql/advisory_lock.sql index 8513ab8e98f..f1bff60fd37 100644 --- a/src/test/regress/sql/advisory_lock.sql +++ b/src/test/regress/sql/advisory_lock.sql @@ -4,6 +4,8 @@ SELECT oid AS datoid FROM pg_database WHERE datname = current_database() \gset +SELECT pg_stat_reset_shared('lock'); + BEGIN; SELECT @@ -26,12 +28,14 @@ SELECT pg_advisory_unlock(1), pg_advisory_unlock_shared(2), pg_advisory_unlock(1, 1), pg_advisory_unlock_shared(2, 2); +SELECT pg_stat_force_next_flush(); -- automatically release xact locks at commit COMMIT; SELECT count(*) FROM pg_locks WHERE locktype = 'advisory' AND database = :datoid; +SELECT requests FROM pg_stat_lock WHERE locktype = 'advisory'; BEGIN; -- 2.34.1 --u5iTJ95dbl+YppYN-- ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v3 2/2] Add the pg_stat_lock view @ 2025-07-31 09:35 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Bertrand Drouvot @ 2025-07-31 09:35 UTC (permalink / raw) This new view reports lock statistics. This commit also adds documentation and a few tests. XXX: Bump catversion --- doc/src/sgml/monitoring.sgml | 151 ++++++++++++++++++ src/backend/catalog/system_views.sql | 12 ++ src/backend/utils/activity/pgstat_lock.c | 8 + src/backend/utils/adt/pgstatfuncs.c | 39 +++++ src/include/catalog/pg_proc.dat | 9 ++ src/include/pgstat.h | 1 + src/test/isolation/expected/deadlock-hard.out | 20 ++- src/test/isolation/specs/deadlock-hard.spec | 5 +- src/test/regress/expected/advisory_lock.out | 18 +++ src/test/regress/expected/rules.out | 9 ++ src/test/regress/sql/advisory_lock.sql | 4 + 11 files changed, 274 insertions(+), 2 deletions(-) 51.5% doc/src/sgml/ 3.3% src/backend/catalog/ 14.3% src/backend/utils/adt/ 5.7% src/include/catalog/ 8.4% src/test/isolation/expected/ 5.9% src/test/isolation/specs/ 6.7% src/test/regress/expected/ 3.8% src/ diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index b77d189a500..927b62cf649 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -493,6 +493,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser </entry> </row> + <row> + <entry><structname>pg_stat_lock</structname><indexterm><primary>pg_stat_lock</primary></indexterm></entry> + <entry> + One row for each lock type, containing cluster-wide locks statistics. + See <link linkend="monitoring-pg-stat-lock-view"> + <structname>pg_stat_lock</structname></link> for details. + </entry> + </row> + <row> <entry><structname>pg_stat_replication_slots</structname><indexterm><primary>pg_stat_replication_slots</primary></indexterm></entry> <entry>One row per replication slot, showing statistics about the @@ -3124,6 +3133,142 @@ description | Waiting for a newly initialized WAL file to reach durable storage </sect2> + + <sect2 id="monitoring-pg-stat-lock-view"> + <title><structname>pg_stat_lock</structname></title> + + <indexterm> + <primary>pg_stat_lock</primary> + </indexterm> + + <para> + The <structname>pg_stat_lock</structname> view will contain one row for each + lock type, showing cluster-wide locks statistics. + </para> + + <table id="pg-stat-lock-view" xreflabel="pg_stat_lock"> + <title><structname>pg_stat_lock</structname> View</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + Column Type + </para> + <para> + Description + </para> + </entry> + </row> + </thead> + <tbody> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>locktype</structfield> <type>text</type> + </para> + <para> + Type of the lockable object: + <literal>relation</literal>, + <literal>extend</literal>, + <literal>frozenid</literal>, + <literal>page</literal>, + <literal>tuple</literal>, + <literal>transactionid</literal>, + <literal>virtualxid</literal>, + <literal>spectoken</literal>, + <literal>object</literal>, + <literal>userlock</literal>, + <literal>advisory</literal>, or + <literal>applytransaction</literal>. + (See also <xref linkend="wait-event-lock-table"/>.) + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>requests</structfield> <type>bigint</type> + </para> + <para> + Number of requests for this lock type. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>waits</structfield> <type>bigint</type> + </para> + <para> + Number of times requests for this lock type had to wait. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>timeouts</structfield> <type>bigint</type> + </para> + <para> + Number of times requests for this lock type had to wait longer + than <varname>lock_timeout</varname>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>deadlock_timeouts</structfield> <type>bigint</type> + </para> + <para> + Number of times requests for this lock type had to wait longer + than <varname>deadlock_timeout</varname>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>deadlocks</structfield> <type>bigint</type> + </para> + <para> + Number of times a deadlock occurred on this lock type. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>fastpath</structfield> <type>bigint</type> + </para> + <para> + Number of times this lock type was taken via fast path. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>stats_reset</structfield> <type>timestamp with time zone</type> + </para> + <para> + Time at which these statistics were last reset. + </para> + </entry> + </row> + </tbody> + </tgroup> + </table> + </sect2> + <sect2 id="monitoring-pg-stat-bgwriter-view"> <title><structname>pg_stat_bgwriter</structname></title> @@ -5195,6 +5340,12 @@ description | Waiting for a newly initialized WAL file to reach durable storage <structname>pg_stat_io</structname> view. </para> </listitem> + <listitem> + <para> + <literal>lock</literal>: Reset all the counters shown in the + <structname>pg_stat_lock</structname> view. + </para> + </listitem> <listitem> <para> <literal>recovery_prefetch</literal>: Reset all the counters shown in diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 1ea8f1faa9e..e30c25ced31 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -985,6 +985,18 @@ CREATE VIEW pg_stat_slru AS s.stats_reset FROM pg_stat_get_slru() s; +CREATE VIEW pg_stat_lock AS + SELECT + l.locktype, + l.requests, + l.waits, + l.timeouts, + l.deadlock_timeouts, + l.deadlocks, + l.fastpath, + l.stats_reset + FROM pg_stat_get_lock() l; + CREATE VIEW pg_stat_wal_receiver AS SELECT s.pid, diff --git a/src/backend/utils/activity/pgstat_lock.c b/src/backend/utils/activity/pgstat_lock.c index fb4ed5c7362..73bdeb5ff66 100644 --- a/src/backend/utils/activity/pgstat_lock.c +++ b/src/backend/utils/activity/pgstat_lock.c @@ -21,6 +21,14 @@ static PgStat_PendingLock PendingLockStats; static bool have_lockstats = false; +PgStat_Lock * +pgstat_fetch_stat_lock(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_LOCK); + + return &pgStatLocal.snapshot.lock; +} + /* * Simpler wrapper of pgstat_lock_flush_cb() */ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 73ca0bb0b7f..4ca4a3f3b9b 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1725,6 +1725,42 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) wal_stats->stat_reset_timestamp)); } +Datum +pg_stat_get_lock(PG_FUNCTION_ARGS) +{ +#define PG_STAT_LOCK_COLS 8 + ReturnSetInfo *rsinfo; + PgStat_Lock *lock_stats; + + InitMaterializedSRF(fcinfo, 0); + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + lock_stats = pgstat_fetch_stat_lock(); + + for (int lcktype = 0; lcktype <= LOCKTAG_LAST_TYPE; lcktype++) + { + const char *locktypename; + Datum values[PG_STAT_LOCK_COLS] = {0}; + bool nulls[PG_STAT_LOCK_COLS] = {0}; + PgStat_LockEntry *lck_stats = &lock_stats->stats[lcktype]; + + locktypename = LockTagTypeNames[lcktype]; + + values[0] = CStringGetTextDatum(locktypename); + values[1] = Int64GetDatum(lck_stats->requests); + values[2] = Int64GetDatum(lck_stats->waits); + values[3] = Int64GetDatum(lck_stats->timeouts); + values[4] = Int64GetDatum(lck_stats->deadlock_timeouts); + values[5] = Int64GetDatum(lck_stats->deadlocks); + values[6] = Int64GetDatum(lck_stats->fastpath); + values[7] = TimestampTzGetDatum(lock_stats->stat_reset_timestamp); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} + /* * Returns statistics of SLRU caches. */ @@ -1909,6 +1945,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER); pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); pgstat_reset_of_kind(PGSTAT_KIND_IO); + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); @@ -1926,6 +1963,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); else if (strcmp(target, "io") == 0) pgstat_reset_of_kind(PGSTAT_KIND_IO); + else if (strcmp(target, "lock") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); else if (strcmp(target, "recovery_prefetch") == 0) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 83f6501df38..a0c47f6888c 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6026,6 +6026,15 @@ proargnames => '{backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}', prosrc => 'pg_stat_get_io' }, +{ oid => '9375', descr => 'statistics: per lock type statistics', + proname => 'pg_stat_get_lock', prorows => '10', proretset => 't', + provolatile => 'v', proparallel => 'r', prorettype => 'record', + proargtypes => '', + proallargtypes => '{text,int8,int8,int8,int8,int8,int8,timestamptz}', + proargmodes => '{o,o,o,o,o,o,o,o}', + proargnames => '{locktype,requests,waits,timeouts,deadlock_timeouts,deadlocks,fastpath,stats_reset}', + prosrc => 'pg_stat_get_lock' }, + { oid => '6386', descr => 'statistics: backend IO statistics', proname => 'pg_stat_get_backend_io', prorows => '5', proretset => 't', provolatile => 'v', proparallel => 'r', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index cbe226b9a07..c16c3335755 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -647,6 +647,7 @@ extern void pgstat_count_lock_timeouts(uint8 locktag_type); extern void pgstat_count_lock_deadlock_timeouts(uint8 locktag_type); extern void pgstat_count_lock_deadlocks(uint8 locktag_type); extern void pgstat_count_lock_fastpath(uint8 locktag_type); +extern PgStat_Lock *pgstat_fetch_stat_lock(void); /* * Functions in pgstat_database.c diff --git a/src/test/isolation/expected/deadlock-hard.out b/src/test/isolation/expected/deadlock-hard.out index 460653f2b86..ff448da5299 100644 --- a/src/test/isolation/expected/deadlock-hard.out +++ b/src/test/isolation/expected/deadlock-hard.out @@ -1,6 +1,12 @@ Parsed test spec with 8 sessions -starting permutation: s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8 s8a1 s8c s7c s6c s5c s4c s3c s2c s1c +starting permutation: s1rl s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8 s8a1 s8c s8f s7c s6c s5c s4c s3c s2c s1c s1sl +step s1rl: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + step s1a1: LOCK TABLE a1; step s2a2: LOCK TABLE a2; step s3a3: LOCK TABLE a3; @@ -21,6 +27,12 @@ step s8a1: <... completed> ERROR: deadlock detected step s7a8: <... completed> step s8c: COMMIT; +step s8f: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + step s7c: COMMIT; step s6a7: <... completed> step s6c: COMMIT; @@ -34,3 +46,9 @@ step s2a3: <... completed> step s2c: COMMIT; step s1a2: <... completed> step s1c: COMMIT; +step s1sl: SELECT deadlocks > 0, deadlock_timeouts > 0 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column? +--------+-------- +t |t +(1 row) + diff --git a/src/test/isolation/specs/deadlock-hard.spec b/src/test/isolation/specs/deadlock-hard.spec index 60bedca237a..6e8330662b4 100644 --- a/src/test/isolation/specs/deadlock-hard.spec +++ b/src/test/isolation/specs/deadlock-hard.spec @@ -25,6 +25,8 @@ setup { BEGIN; SET deadlock_timeout = '100s'; } step s1a1 { LOCK TABLE a1; } step s1a2 { LOCK TABLE a2; } step s1c { COMMIT; } +step s1sl { SELECT deadlocks > 0, deadlock_timeouts > 0 FROM pg_stat_lock WHERE locktype = 'relation'; } +step s1rl { SELECT pg_stat_reset_shared('lock'); } session s2 setup { BEGIN; SET deadlock_timeout = '100s'; } @@ -67,6 +69,7 @@ setup { BEGIN; SET deadlock_timeout = '10ms'; } step s8a8 { LOCK TABLE a8; } step s8a1 { LOCK TABLE a1; } step s8c { COMMIT; } +step s8f { SELECT pg_stat_force_next_flush(); } # Note: when s8a1 detects the deadlock and fails, s7a8 is released, making # it timing-dependent which query completion is received first by the tester. @@ -76,4 +79,4 @@ step s8c { COMMIT; } # dummy blocking mark to s8a1 to ensure it will be reported as "waiting" # regardless of that. -permutation s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8(s8a1) s8a1(*) s8c s7c s6c s5c s4c s3c s2c s1c +permutation s1rl s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8(s8a1) s8a1(*) s8c s8f s7c s6c s5c s4c s3c s2c s1c s1sl diff --git a/src/test/regress/expected/advisory_lock.out b/src/test/regress/expected/advisory_lock.out index 02e07765ac2..fdaa1756ba4 100644 --- a/src/test/regress/expected/advisory_lock.out +++ b/src/test/regress/expected/advisory_lock.out @@ -2,6 +2,12 @@ -- ADVISORY LOCKS -- SELECT oid AS datoid FROM pg_database WHERE datname = current_database() \gset +SELECT pg_stat_reset_shared('lock'); + pg_stat_reset_shared +---------------------- + +(1 row) + BEGIN; SELECT pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2), @@ -48,6 +54,12 @@ WARNING: you don't own a lock of type ShareLock f | f | f | f (1 row) +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + -- automatically release xact locks at commit COMMIT; SELECT count(*) FROM pg_locks WHERE locktype = 'advisory' AND database = :datoid; @@ -56,6 +68,12 @@ SELECT count(*) FROM pg_locks WHERE locktype = 'advisory' AND database = :datoid 0 (1 row) +SELECT requests FROM pg_stat_lock WHERE locktype = 'advisory'; + requests +---------- + 4 +(1 row) + BEGIN; -- holding both session and xact locks on the same objects, xact first SELECT diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index f9bc213e5a1..8ee2e4cbea1 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1951,6 +1951,15 @@ pg_stat_io| SELECT backend_type, fsync_time, stats_reset FROM pg_stat_get_io() b(backend_type, object, context, reads, read_bytes, read_time, writes, write_bytes, write_time, writebacks, writeback_time, extends, extend_bytes, extend_time, hits, evictions, reuses, fsyncs, fsync_time, stats_reset); +pg_stat_lock| SELECT locktype, + requests, + waits, + timeouts, + deadlock_timeouts, + deadlocks, + fastpath, + stats_reset + FROM pg_stat_get_lock() l(locktype, requests, waits, timeouts, deadlock_timeouts, deadlocks, fastpath, stats_reset); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, diff --git a/src/test/regress/sql/advisory_lock.sql b/src/test/regress/sql/advisory_lock.sql index 8513ab8e98f..f1bff60fd37 100644 --- a/src/test/regress/sql/advisory_lock.sql +++ b/src/test/regress/sql/advisory_lock.sql @@ -4,6 +4,8 @@ SELECT oid AS datoid FROM pg_database WHERE datname = current_database() \gset +SELECT pg_stat_reset_shared('lock'); + BEGIN; SELECT @@ -26,12 +28,14 @@ SELECT pg_advisory_unlock(1), pg_advisory_unlock_shared(2), pg_advisory_unlock(1, 1), pg_advisory_unlock_shared(2, 2); +SELECT pg_stat_force_next_flush(); -- automatically release xact locks at commit COMMIT; SELECT count(*) FROM pg_locks WHERE locktype = 'advisory' AND database = :datoid; +SELECT requests FROM pg_stat_lock WHERE locktype = 'advisory'; BEGIN; -- 2.34.1 --PI+wla+m5/GDNJVD-- ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v4 2/2] Add the pg_stat_lock view @ 2025-07-31 09:35 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Bertrand Drouvot @ 2025-07-31 09:35 UTC (permalink / raw) This new view reports lock statistics. This commit also adds documentation and a few tests. XXX: Bump catversion --- doc/src/sgml/monitoring.sgml | 117 ++++++++++++++++++ src/backend/catalog/system_views.sql | 10 ++ src/backend/utils/activity/pgstat_lock.c | 8 ++ src/backend/utils/adt/pgstatfuncs.c | 40 ++++++ src/include/catalog/pg_proc.dat | 9 ++ src/include/pgstat.h | 1 + src/test/isolation/expected/deadlock-hard.out | 20 ++- src/test/isolation/specs/deadlock-hard.spec | 5 +- src/test/regress/expected/advisory_lock.out | 18 +++ src/test/regress/expected/rules.out | 7 ++ src/test/regress/sql/advisory_lock.sql | 4 + 11 files changed, 237 insertions(+), 2 deletions(-) 46.2% doc/src/sgml/ 3.2% src/backend/catalog/ 16.3% src/backend/utils/adt/ 6.2% src/include/catalog/ 9.3% src/test/isolation/expected/ 6.7% src/test/isolation/specs/ 7.3% src/test/regress/expected/ 4.4% src/ diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index b77d189a500..1cba84c1542 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -493,6 +493,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser </entry> </row> + <row> + <entry><structname>pg_stat_lock</structname><indexterm><primary>pg_stat_lock</primary></indexterm></entry> + <entry> + One row for each lock type, containing cluster-wide locks statistics. + See <link linkend="monitoring-pg-stat-lock-view"> + <structname>pg_stat_lock</structname></link> for details. + </entry> + </row> + <row> <entry><structname>pg_stat_replication_slots</structname><indexterm><primary>pg_stat_replication_slots</primary></indexterm></entry> <entry>One row per replication slot, showing statistics about the @@ -3124,6 +3133,108 @@ description | Waiting for a newly initialized WAL file to reach durable storage </sect2> + + <sect2 id="monitoring-pg-stat-lock-view"> + <title><structname>pg_stat_lock</structname></title> + + <indexterm> + <primary>pg_stat_lock</primary> + </indexterm> + + <para> + The <structname>pg_stat_lock</structname> view will contain one row for each + lock type, showing cluster-wide locks statistics. + </para> + + <table id="pg-stat-lock-view" xreflabel="pg_stat_lock"> + <title><structname>pg_stat_lock</structname> View</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + Column Type + </para> + <para> + Description + </para> + </entry> + </row> + </thead> + <tbody> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>locktype</structfield> <type>text</type> + </para> + <para> + Type of the lockable object. See <link linkend="view-pg-locks"> + <structname>pg_stat_lock</structname></link> for details. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>requests</structfield> <type>bigint</type> + </para> + <para> + Number of requests for this lock type. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>timeouts</structfield> <type>bigint</type> + </para> + <para> + Number of times requests for this lock type had to wait longer + than <varname>lock_timeout</varname>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>deadlock_timeouts</structfield> <type>bigint</type> + </para> + <para> + Number of times requests for this lock type had to wait longer + than <varname>deadlock_timeout</varname>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>fastpath</structfield> <type>bigint</type> + </para> + <para> + Number of times this lock type was taken via fast path. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>stats_reset</structfield> <type>timestamp with time zone</type> + </para> + <para> + Time at which these statistics were last reset. + </para> + </entry> + </row> + </tbody> + </tgroup> + </table> + </sect2> + <sect2 id="monitoring-pg-stat-bgwriter-view"> <title><structname>pg_stat_bgwriter</structname></title> @@ -5195,6 +5306,12 @@ description | Waiting for a newly initialized WAL file to reach durable storage <structname>pg_stat_io</structname> view. </para> </listitem> + <listitem> + <para> + <literal>lock</literal>: Reset all the counters shown in the + <structname>pg_stat_lock</structname> view. + </para> + </listitem> <listitem> <para> <literal>recovery_prefetch</literal>: Reset all the counters shown in diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 1ea8f1faa9e..a51ae67de05 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -985,6 +985,16 @@ CREATE VIEW pg_stat_slru AS s.stats_reset FROM pg_stat_get_slru() s; +CREATE VIEW pg_stat_lock AS + SELECT + l.locktype, + l.requests, + l.timeouts, + l.deadlock_timeouts, + l.fastpath, + l.stats_reset + FROM pg_stat_get_lock() l; + CREATE VIEW pg_stat_wal_receiver AS SELECT s.pid, diff --git a/src/backend/utils/activity/pgstat_lock.c b/src/backend/utils/activity/pgstat_lock.c index 110a370b875..e26e24c260c 100644 --- a/src/backend/utils/activity/pgstat_lock.c +++ b/src/backend/utils/activity/pgstat_lock.c @@ -21,6 +21,14 @@ static PgStat_PendingLock PendingLockStats; static bool have_lockstats = false; +PgStat_Lock * +pgstat_fetch_stat_lock(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_LOCK); + + return &pgStatLocal.snapshot.lock; +} + /* * Simpler wrapper of pgstat_lock_flush_cb() */ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index b1df96e7b0b..6a699da8bf0 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1737,6 +1737,43 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) wal_stats->stat_reset_timestamp)); } +Datum +pg_stat_get_lock(PG_FUNCTION_ARGS) +{ +#define PG_STAT_LOCK_COLS 6 + ReturnSetInfo *rsinfo; + PgStat_Lock *lock_stats; + + InitMaterializedSRF(fcinfo, 0); + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + lock_stats = pgstat_fetch_stat_lock(); + + for (int lcktype = 0; lcktype <= LOCKTAG_LAST_TYPE; lcktype++) + { + const char *locktypename; + Datum values[PG_STAT_LOCK_COLS] = {0}; + bool nulls[PG_STAT_LOCK_COLS] = {0}; + PgStat_LockEntry *lck_stats = &lock_stats->stats[lcktype]; + int i = 0; + + locktypename = LockTagTypeNames[lcktype]; + + values[i++] = CStringGetTextDatum(locktypename); + values[i++] = Int64GetDatum(lck_stats->requests); + values[i++] = Int64GetDatum(lck_stats->timeouts); + values[i++] = Int64GetDatum(lck_stats->deadlock_timeouts); + values[i++] = Int64GetDatum(lck_stats->fastpath); + values[i] = TimestampTzGetDatum(lock_stats->stat_reset_timestamp); + + Assert(i + 1 == PG_STAT_LOCK_COLS); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} + /* * Returns statistics of SLRU caches. */ @@ -1921,6 +1958,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER); pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); pgstat_reset_of_kind(PGSTAT_KIND_IO); + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); @@ -1938,6 +1976,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); else if (strcmp(target, "io") == 0) pgstat_reset_of_kind(PGSTAT_KIND_IO); + else if (strcmp(target, "lock") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); else if (strcmp(target, "recovery_prefetch") == 0) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 83f6501df38..e208ebdbbc3 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6026,6 +6026,15 @@ proargnames => '{backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}', prosrc => 'pg_stat_get_io' }, +{ oid => '9375', descr => 'statistics: per lock type statistics', + proname => 'pg_stat_get_lock', prorows => '10', proretset => 't', + provolatile => 'v', proparallel => 'r', prorettype => 'record', + proargtypes => '', + proallargtypes => '{text,int8,int8,int8,int8,timestamptz}', + proargmodes => '{o,o,o,o,o,o}', + proargnames => '{locktype,requests,timeouts,deadlock_timeouts,fastpath,stats_reset}', + prosrc => 'pg_stat_get_lock' }, + { oid => '6386', descr => 'statistics: backend IO statistics', proname => 'pg_stat_get_backend_io', prorows => '5', proretset => 't', provolatile => 'v', proparallel => 'r', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 8460e2db159..b06a261572b 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -643,6 +643,7 @@ extern void pgstat_count_lock_requests(uint8 locktag_type); extern void pgstat_count_lock_timeouts(uint8 locktag_type); extern void pgstat_count_lock_deadlock_timeouts(uint8 locktag_type); extern void pgstat_count_lock_fastpath(uint8 locktag_type); +extern PgStat_Lock *pgstat_fetch_stat_lock(void); /* * Functions in pgstat_database.c diff --git a/src/test/isolation/expected/deadlock-hard.out b/src/test/isolation/expected/deadlock-hard.out index 460653f2b86..5ae5a8bf953 100644 --- a/src/test/isolation/expected/deadlock-hard.out +++ b/src/test/isolation/expected/deadlock-hard.out @@ -1,6 +1,12 @@ Parsed test spec with 8 sessions -starting permutation: s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8 s8a1 s8c s7c s6c s5c s4c s3c s2c s1c +starting permutation: s1rl s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8 s8a1 s8c s8f s7c s6c s5c s4c s3c s2c s1c s1sl +step s1rl: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + step s1a1: LOCK TABLE a1; step s2a2: LOCK TABLE a2; step s3a3: LOCK TABLE a3; @@ -21,6 +27,12 @@ step s8a1: <... completed> ERROR: deadlock detected step s7a8: <... completed> step s8c: COMMIT; +step s8f: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + step s7c: COMMIT; step s6a7: <... completed> step s6c: COMMIT; @@ -34,3 +46,9 @@ step s2a3: <... completed> step s2c: COMMIT; step s1a2: <... completed> step s1c: COMMIT; +step s1sl: SELECT deadlock_timeouts > 0 FROM pg_stat_lock WHERE locktype = 'relation'; +?column? +-------- +t +(1 row) + diff --git a/src/test/isolation/specs/deadlock-hard.spec b/src/test/isolation/specs/deadlock-hard.spec index 60bedca237a..d9ed99836e3 100644 --- a/src/test/isolation/specs/deadlock-hard.spec +++ b/src/test/isolation/specs/deadlock-hard.spec @@ -25,6 +25,8 @@ setup { BEGIN; SET deadlock_timeout = '100s'; } step s1a1 { LOCK TABLE a1; } step s1a2 { LOCK TABLE a2; } step s1c { COMMIT; } +step s1sl { SELECT deadlock_timeouts > 0 FROM pg_stat_lock WHERE locktype = 'relation'; } +step s1rl { SELECT pg_stat_reset_shared('lock'); } session s2 setup { BEGIN; SET deadlock_timeout = '100s'; } @@ -67,6 +69,7 @@ setup { BEGIN; SET deadlock_timeout = '10ms'; } step s8a8 { LOCK TABLE a8; } step s8a1 { LOCK TABLE a1; } step s8c { COMMIT; } +step s8f { SELECT pg_stat_force_next_flush(); } # Note: when s8a1 detects the deadlock and fails, s7a8 is released, making # it timing-dependent which query completion is received first by the tester. @@ -76,4 +79,4 @@ step s8c { COMMIT; } # dummy blocking mark to s8a1 to ensure it will be reported as "waiting" # regardless of that. -permutation s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8(s8a1) s8a1(*) s8c s7c s6c s5c s4c s3c s2c s1c +permutation s1rl s1a1 s2a2 s3a3 s4a4 s5a5 s6a6 s7a7 s8a8 s1a2 s2a3 s3a4 s4a5 s5a6 s6a7 s7a8(s8a1) s8a1(*) s8c s8f s7c s6c s5c s4c s3c s2c s1c s1sl diff --git a/src/test/regress/expected/advisory_lock.out b/src/test/regress/expected/advisory_lock.out index 02e07765ac2..fdaa1756ba4 100644 --- a/src/test/regress/expected/advisory_lock.out +++ b/src/test/regress/expected/advisory_lock.out @@ -2,6 +2,12 @@ -- ADVISORY LOCKS -- SELECT oid AS datoid FROM pg_database WHERE datname = current_database() \gset +SELECT pg_stat_reset_shared('lock'); + pg_stat_reset_shared +---------------------- + +(1 row) + BEGIN; SELECT pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2), @@ -48,6 +54,12 @@ WARNING: you don't own a lock of type ShareLock f | f | f | f (1 row) +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + -- automatically release xact locks at commit COMMIT; SELECT count(*) FROM pg_locks WHERE locktype = 'advisory' AND database = :datoid; @@ -56,6 +68,12 @@ SELECT count(*) FROM pg_locks WHERE locktype = 'advisory' AND database = :datoid 0 (1 row) +SELECT requests FROM pg_stat_lock WHERE locktype = 'advisory'; + requests +---------- + 4 +(1 row) + BEGIN; -- holding both session and xact locks on the same objects, xact first SELECT diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 78a37d9fc8f..80999465baf 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1951,6 +1951,13 @@ pg_stat_io| SELECT backend_type, fsync_time, stats_reset FROM pg_stat_get_io() b(backend_type, object, context, reads, read_bytes, read_time, writes, write_bytes, write_time, writebacks, writeback_time, extends, extend_bytes, extend_time, hits, evictions, reuses, fsyncs, fsync_time, stats_reset); +pg_stat_lock| SELECT locktype, + requests, + timeouts, + deadlock_timeouts, + fastpath, + stats_reset + FROM pg_stat_get_lock() l(locktype, requests, timeouts, deadlock_timeouts, fastpath, stats_reset); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, diff --git a/src/test/regress/sql/advisory_lock.sql b/src/test/regress/sql/advisory_lock.sql index 8513ab8e98f..f1bff60fd37 100644 --- a/src/test/regress/sql/advisory_lock.sql +++ b/src/test/regress/sql/advisory_lock.sql @@ -4,6 +4,8 @@ SELECT oid AS datoid FROM pg_database WHERE datname = current_database() \gset +SELECT pg_stat_reset_shared('lock'); + BEGIN; SELECT @@ -26,12 +28,14 @@ SELECT pg_advisory_unlock(1), pg_advisory_unlock_shared(2), pg_advisory_unlock(1, 1), pg_advisory_unlock_shared(2, 2); +SELECT pg_stat_force_next_flush(); -- automatically release xact locks at commit COMMIT; SELECT count(*) FROM pg_locks WHERE locktype = 'advisory' AND database = :datoid; +SELECT requests FROM pg_stat_lock WHERE locktype = 'advisory'; BEGIN; -- 2.34.1 --3ZD47sYrxKE4JxfA-- ^ permalink raw reply [nested|flat] 14+ messages in thread
* [PATCH v6 2/2] Add the pg_stat_lock view @ 2026-02-19 10:19 Bertrand Drouvot <[email protected]> 0 siblings, 0 replies; 14+ messages in thread From: Bertrand Drouvot @ 2026-02-19 10:19 UTC (permalink / raw) This new view reports lock statistics. Note that it does not omit combinations which do not make sense (as pg_locks does). Also wait_time is reported as bigint as the deadlock_timeout default value is 1s. This commit also adds documentation and a few tests. XXX: Bump catversion --- doc/src/sgml/config.sgml | 4 +- doc/src/sgml/monitoring.sgml | 125 +++++++++++++++ src/backend/catalog/system_views.sql | 10 ++ src/backend/utils/activity/pgstat_lock.c | 8 + src/backend/utils/adt/pgstatfuncs.c | 40 +++++ src/include/catalog/pg_proc.dat | 9 ++ src/include/pgstat.h | 1 + src/test/isolation/expected/stats.out | 189 +++++++++++++++++++++++ src/test/isolation/expected/stats_1.out | 189 +++++++++++++++++++++++ src/test/isolation/specs/stats.spec | 95 ++++++++++++ src/test/regress/expected/rules.out | 7 + src/test/regress/expected/stats.out | 48 ++++++ src/test/regress/sql/stats.sql | 36 +++++ 13 files changed, 760 insertions(+), 1 deletion(-) 17.5% doc/src/sgml/ 4.9% src/backend/utils/adt/ 53.2% src/test/isolation/expected/ 11.1% src/test/isolation/specs/ 5.5% src/test/regress/expected/ 3.8% src/test/regress/sql/ 3.6% src/ diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 0e868fb03e4..b3c353d6095 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -8854,7 +8854,9 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; <para> Enables timing of lock waits. This parameter is on by default, as it tracks only the timings for successful acquisitions that waited longer than - <xref linkend="guc-deadlock-timeout"/>. + <xref linkend="guc-deadlock-timeout"/>. Lock timing information is + displayed in the <link linkend="monitoring-pg-stat-lock-view"> + <structname>pg_stat_lock</structname></link> view. Only superusers and users with the appropriate <literal>SET</literal> privilege can change this setting. </para> diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index b77d189a500..277275fdcb5 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -493,6 +493,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser </entry> </row> + <row> + <entry><structname>pg_stat_lock</structname><indexterm><primary>pg_stat_lock</primary></indexterm></entry> + <entry> + One row for each lock type, containing cluster-wide locks statistics. + See <link linkend="monitoring-pg-stat-lock-view"> + <structname>pg_stat_lock</structname></link> for details. + </entry> + </row> + <row> <entry><structname>pg_stat_replication_slots</structname><indexterm><primary>pg_stat_replication_slots</primary></indexterm></entry> <entry>One row per replication slot, showing statistics about the @@ -3124,6 +3133,116 @@ description | Waiting for a newly initialized WAL file to reach durable storage </sect2> + + <sect2 id="monitoring-pg-stat-lock-view"> + <title><structname>pg_stat_lock</structname></title> + + <indexterm> + <primary>pg_stat_lock</primary> + </indexterm> + + <para> + The <structname>pg_stat_lock</structname> view will contain one row for each + lock type, showing cluster-wide locks statistics. + </para> + + <table id="pg-stat-lock-view" xreflabel="pg_stat_lock"> + <title><structname>pg_stat_lock</structname> View</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + Column Type + </para> + <para> + Description + </para> + </entry> + </row> + </thead> + <tbody> + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>locktype</structfield> <type>text</type> + </para> + <para> + Type of the lockable object. See <link linkend="view-pg-locks"> + <structname>pg_locks</structname></link> for details. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>waits</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type had to wait because of a + conflicting lock. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>timed_waits</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type had to wait because of a + conflicting lock. Only incremented when <xref linkend="guc-track-lock-timing"/> + is enabled and the lock was successfully acquired after waiting longer + than <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>wait_time</structfield> <type>bigint</type> + </para> + <para> + Total time spent waiting for locks of this type, in milliseconds. + Only incremented when <xref linkend="guc-track-lock-timing"/> is enabled and + the lock was successfully acquired after waiting longer than + <xref linkend="guc-deadlock-timeout"/>. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>fastpath_exceeded</structfield> <type>bigint</type> + </para> + <para> + Number of times a lock of this type could not be acquired via fast path + because the fast path slot limit was exceeded. You may want to increase + <xref linkend="guc-max-locks-per-transaction"/> if you feel this counter + is too high. + </para> + </entry> + </row> + + <row> + <entry role="catalog_table_entry"> + <para role="column_definition"> + <structfield>stats_reset</structfield> <type>timestamp with time zone</type> + </para> + <para> + Time at which these statistics were last reset. + </para> + </entry> + </row> + </tbody> + </tgroup> + </table> + </sect2> + <sect2 id="monitoring-pg-stat-bgwriter-view"> <title><structname>pg_stat_bgwriter</structname></title> @@ -5195,6 +5314,12 @@ description | Waiting for a newly initialized WAL file to reach durable storage <structname>pg_stat_io</structname> view. </para> </listitem> + <listitem> + <para> + <literal>lock</literal>: Reset all the counters shown in the + <structname>pg_stat_lock</structname> view. + </para> + </listitem> <listitem> <para> <literal>recovery_prefetch</literal>: Reset all the counters shown in diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 1ea8f1faa9e..dcf12a202e0 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -985,6 +985,16 @@ CREATE VIEW pg_stat_slru AS s.stats_reset FROM pg_stat_get_slru() s; +CREATE VIEW pg_stat_lock AS + SELECT + l.locktype, + l.waits, + l.timed_waits, + l.wait_time, + l.fastpath_exceeded, + l.stats_reset + FROM pg_stat_get_lock() l; + CREATE VIEW pg_stat_wal_receiver AS SELECT s.pid, diff --git a/src/backend/utils/activity/pgstat_lock.c b/src/backend/utils/activity/pgstat_lock.c index b410f376d49..451fba4f8d9 100644 --- a/src/backend/utils/activity/pgstat_lock.c +++ b/src/backend/utils/activity/pgstat_lock.c @@ -21,6 +21,14 @@ static PgStat_PendingLock PendingLockStats; static bool have_lockstats = false; +PgStat_Lock * +pgstat_fetch_stat_lock(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_LOCK); + + return &pgStatLocal.snapshot.lock; +} + /* * Simpler wrapper of pgstat_lock_flush_cb() */ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index b1df96e7b0b..3b7cbdb82be 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1737,6 +1737,43 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) wal_stats->stat_reset_timestamp)); } +Datum +pg_stat_get_lock(PG_FUNCTION_ARGS) +{ +#define PG_STAT_LOCK_COLS 6 + ReturnSetInfo *rsinfo; + PgStat_Lock *lock_stats; + + InitMaterializedSRF(fcinfo, 0); + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + lock_stats = pgstat_fetch_stat_lock(); + + for (int lcktype = 0; lcktype <= LOCKTAG_LAST_TYPE; lcktype++) + { + const char *locktypename; + Datum values[PG_STAT_LOCK_COLS] = {0}; + bool nulls[PG_STAT_LOCK_COLS] = {0}; + PgStat_LockEntry *lck_stats = &lock_stats->stats[lcktype]; + int i = 0; + + locktypename = LockTagTypeNames[lcktype]; + + values[i++] = CStringGetTextDatum(locktypename); + values[i++] = Int64GetDatum(lck_stats->waits); + values[i++] = Int64GetDatum(lck_stats->timed_waits); + values[i++] = Int64GetDatum(lck_stats->wait_time); + values[i++] = Int64GetDatum(lck_stats->fastpath_exceeded); + values[i] = TimestampTzGetDatum(lock_stats->stat_reset_timestamp); + + Assert(i + 1 == PG_STAT_LOCK_COLS); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} + /* * Returns statistics of SLRU caches. */ @@ -1921,6 +1958,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER); pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); pgstat_reset_of_kind(PGSTAT_KIND_IO); + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); @@ -1938,6 +1976,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); else if (strcmp(target, "io") == 0) pgstat_reset_of_kind(PGSTAT_KIND_IO); + else if (strcmp(target, "lock") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); else if (strcmp(target, "recovery_prefetch") == 0) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index dac40992cbc..3cd497a8e1f 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6027,6 +6027,15 @@ proargnames => '{backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}', prosrc => 'pg_stat_get_io' }, +{ oid => '9375', descr => 'statistics: per lock type statistics', + proname => 'pg_stat_get_lock', prorows => '10', proretset => 't', + provolatile => 'v', proparallel => 'r', prorettype => 'record', + proargtypes => '', + proallargtypes => '{text,int8,int8,int8,int8,timestamptz}', + proargmodes => '{o,o,o,o,o,o}', + proargnames => '{locktype,waits,timed_waits,wait_time,fastpath_exceeded,stats_reset}', + prosrc => 'pg_stat_get_lock' }, + { oid => '6386', descr => 'statistics: backend IO statistics', proname => 'pg_stat_get_backend_io', prorows => '5', proretset => 't', provolatile => 'v', proparallel => 'r', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 615ccf540e6..39441d9698a 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -642,6 +642,7 @@ extern void pgstat_lock_flush(bool nowait); extern void pgstat_count_lock_waits(uint8 locktag_type); extern void pgstat_count_lock_fastpath_exceeded(uint8 locktag_type); extern void pgstat_count_lock_timed_wait(uint8 locktag_type, long msecs); +extern PgStat_Lock *pgstat_fetch_stat_lock(void); /* * Functions in pgstat_database.c diff --git a/src/test/isolation/expected/stats.out b/src/test/isolation/expected/stats.out index cfad309ccf3..f9cd78f03b3 100644 --- a/src/test/isolation/expected/stats.out +++ b/src/test/isolation/expected/stats.out @@ -3751,3 +3751,192 @@ test_stat_func| 1|t |t (1 row) step s1_commit: COMMIT; + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_track_lock_timing s2_set_deadlock_timeout s2_set_track_lock_timing s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_track_lock_timing: SET track_lock_timing = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_track_lock_timing: SET track_lock_timing = on; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column?|?column? +--------+--------+-------- +t |t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_track_lock_timing s2_set_deadlock_timeout s2_set_track_lock_timing s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_track_lock_timing: SET track_lock_timing = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_track_lock_timing: SET track_lock_timing = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; +?column?|?column?|?column? +--------+--------+-------- +t |t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_track_lock_timing s2_set_deadlock_timeout s2_set_track_lock_timing s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_track_lock_timing: SET track_lock_timing = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_track_lock_timing: SET track_lock_timing = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; +?column?|?column?|?column? +--------+--------+-------- +t |t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_track_lock_timing s2_set_deadlock_timeout s2_unset_track_lock_timing s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_track_lock_timing: SET track_lock_timing = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_unset_track_lock_timing: SET track_lock_timing = off; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column?|?column? +--------+--------+-------- +t |f |f +(1 row) + diff --git a/src/test/isolation/expected/stats_1.out b/src/test/isolation/expected/stats_1.out index e1d937784cb..955f6ff5ec0 100644 --- a/src/test/isolation/expected/stats_1.out +++ b/src/test/isolation/expected/stats_1.out @@ -3775,3 +3775,192 @@ test_stat_func| 1|t |t (1 row) step s1_commit: COMMIT; + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_track_lock_timing s2_set_deadlock_timeout s2_set_track_lock_timing s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_track_lock_timing: SET track_lock_timing = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_track_lock_timing: SET track_lock_timing = on; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column?|?column? +--------+--------+-------- +t |t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_track_lock_timing s2_set_deadlock_timeout s2_set_track_lock_timing s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_track_lock_timing: SET track_lock_timing = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_track_lock_timing: SET track_lock_timing = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; +?column?|?column?|?column? +--------+--------+-------- +t |t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_track_lock_timing s2_set_deadlock_timeout s2_set_track_lock_timing s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_track_lock_timing: SET track_lock_timing = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_track_lock_timing: SET track_lock_timing = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; +?column?|?column?|?column? +--------+--------+-------- +t |t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s1_set_track_lock_timing s2_set_deadlock_timeout s2_unset_track_lock_timing s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s1_set_track_lock_timing: SET track_lock_timing = on; +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_unset_track_lock_timing: SET track_lock_timing = off; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; <waiting ...> +step s1_sleep: SELECT pg_sleep(0.5); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; +?column?|?column?|?column? +--------+--------+-------- +t |f |f +(1 row) + diff --git a/src/test/isolation/specs/stats.spec b/src/test/isolation/specs/stats.spec index da16710da0f..7c8e2a9214e 100644 --- a/src/test/isolation/specs/stats.spec +++ b/src/test/isolation/specs/stats.spec @@ -130,6 +130,14 @@ step s1_slru_check_stats { WHERE before.stat = 'blks_zeroed'; } +# Lock stats steps +step s1_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s1_set_track_lock_timing { SET track_lock_timing = on; } +step s1_reset_stat_lock { SELECT pg_stat_reset_shared('lock'); } +step s1_sleep { SELECT pg_sleep(0.5); } +step s1_lock_relation { LOCK TABLE test_stat_tab; } +step s1_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s1_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } session s2 setup { SET stats_fetch_consistency = 'none'; } @@ -164,6 +172,16 @@ step s2_big_notify { SELECT pg_notify('stats_test_use', repeat(i::text, current_setting('block_size')::int / 2)) FROM generate_series(1, 3) g(i); } +# Lock stats steps +step s2_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s2_set_track_lock_timing { SET track_lock_timing = on; } +step s2_unset_track_lock_timing { SET track_lock_timing = off; } +step s2_report_stat_lock_relation { SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'relation'; } +step s2_report_stat_lock_transactionid { SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'transactionid'; } +step s2_report_stat_lock_advisory { SELECT waits > 0, timed_waits = waits, wait_time > 500 FROM pg_stat_lock WHERE locktype = 'advisory'; } +step s2_lock_relation { LOCK TABLE test_stat_tab; } +step s2_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s2_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } ###################### # Function stats tests @@ -765,3 +783,80 @@ permutation s1_clear_snapshot s1_func_stats s1_commit + +###################### +# Lock stats tests +###################### + +# relation lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_track_lock_timing + s2_set_deadlock_timeout + s2_set_track_lock_timing + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation + +# transaction lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_track_lock_timing + s2_set_deadlock_timeout + s2_set_track_lock_timing + s1_table_insert + s1_begin + s1_table_update_k1 + s2_begin + s2_ff + s2_table_update_k1 + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_transactionid + +# advisory lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_track_lock_timing + s2_set_deadlock_timeout + s2_set_track_lock_timing + s1_lock_advisory_lock + s2_begin + s2_ff + s2_lock_advisory_lock + s1_sleep + s1_lock_advisory_unlock + s2_lock_advisory_unlock + s2_commit + s2_report_stat_lock_advisory + +# Ensure track_lock_timing behaves correctly + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s1_set_track_lock_timing + s2_set_deadlock_timeout + s2_unset_track_lock_timing + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 78a37d9fc8f..2fcb48df6c9 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1951,6 +1951,13 @@ pg_stat_io| SELECT backend_type, fsync_time, stats_reset FROM pg_stat_get_io() b(backend_type, object, context, reads, read_bytes, read_time, writes, write_bytes, write_time, writebacks, writeback_time, extends, extend_bytes, extend_time, hits, evictions, reuses, fsyncs, fsync_time, stats_reset); +pg_stat_lock| SELECT locktype, + waits, + timed_waits, + wait_time, + fastpath_exceeded, + stats_reset + FROM pg_stat_get_lock() l(locktype, waits, timed_waits, wait_time, fastpath_exceeded, stats_reset); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index cd00f35bf7a..93de87747d4 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -1910,4 +1910,52 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); (1 row) DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); +SELECT pg_stat_reset_shared('lock'); + pg_stat_reset_shared +---------------------- + +(1 row) + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + count +------- + 0 +(1 row) + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + ?column? +---------- + t +(1 row) + +DROP TABLE part_test; -- End of Stats Test diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 8768e0f27fd..db9948eedb8 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -944,4 +944,40 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); + +SELECT pg_stat_reset_shared('lock'); + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; + +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset + +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + +DROP TABLE part_test; + -- End of Stats Test -- 2.34.1 --7AmA4UfQBKkkaxHa-- ^ permalink raw reply [nested|flat] 14+ messages in thread
end of thread, other threads:[~2026-02-19 10:19 UTC | newest] Thread overview: 14+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2023-10-02 19:55 [PATCH v6 15/15] Trigger authors need not worry about parallelism Karl O. Pinc <[email protected]> 2023-10-02 19:55 [PATCH v7 15/16] Trigger authors need not worry about parallelism Karl O. Pinc <[email protected]> 2024-03-28 10:30 [PATCH v15 4/8] Row pattern recognition patch (planner). Tatsuo Ishii <[email protected]> 2025-07-31 09:35 [PATCH v10 2/2] Add the pg_stat_lock view Bertrand Drouvot <[email protected]> 2025-07-31 09:35 [PATCH v11 3/3] Add the pg_stat_lock view Bertrand Drouvot <[email protected]> 2025-07-31 09:35 [PATCH v1 2/2] Add the pg_stat_lock view Bertrand Drouvot <[email protected]> 2025-07-31 09:35 [PATCH v3 2/2] Add the pg_stat_lock view Bertrand Drouvot <[email protected]> 2025-07-31 09:35 [PATCH v4 2/2] Add the pg_stat_lock view Bertrand Drouvot <[email protected]> 2025-07-31 09:35 [PATCH v8 2/3] Add the pg_stat_lock view Bertrand Drouvot <[email protected]> 2025-07-31 09:35 [PATCH v7 2/3] Add the pg_stat_lock view Bertrand Drouvot <[email protected]> 2025-07-31 09:35 [PATCH v5 2/2] Add the pg_stat_lock view Bertrand Drouvot <[email protected]> 2025-07-31 09:35 [PATCH v9 2/3] Add the pg_stat_lock view Bertrand Drouvot <[email protected]> 2025-07-31 09:35 [PATCH v2 2/2] Add the pg_stat_lock view Bertrand Drouvot <[email protected]> 2026-02-19 10:19 [PATCH v6 2/2] Add the pg_stat_lock view Bertrand Drouvot <[email protected]>
This inbox is served by agora; see mirroring instructions for how to clone and mirror all data and code used for this inbox