From 176973d844c0965c4c7f89025b968790c886f6c0 Mon Sep 17 00:00:00 2001 From: Kyotaro Horiguchi Date: Thu, 16 Nov 2017 15:27:53 +0900 Subject: [PATCH 1/4] Show index scans of the last vacuum in pg_stat_all_tables This number is already shown in the autovacuum completion log or the result of VACUUM VERBOSE, but the number is useful to see whether maintenance_work_mem is large enough so this patch adds the number in pg_stat_all_tables view. --- doc/src/sgml/config.sgml | 9 +++++++++ doc/src/sgml/monitoring.sgml | 5 +++++ src/backend/catalog/system_views.sql | 1 + src/backend/commands/vacuumlazy.c | 3 ++- src/backend/postmaster/pgstat.c | 6 +++++- src/backend/utils/adt/pgstatfuncs.c | 14 ++++++++++++++ src/include/catalog/pg_proc.h | 2 ++ src/include/pgstat.h | 5 ++++- src/test/regress/expected/rules.out | 3 +++ 9 files changed, 45 insertions(+), 3 deletions(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index fc1752f..b51d219 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -1502,6 +1502,15 @@ include_dir 'conf.d' too high. It may be useful to control for this by separately setting . + + Vacuum scans all index pages to remove index entries that pointed to + dead tuples. Finishing vacuum with a minimal number of index scans + reduces the time it takes to complete it, and a new scan is triggered + once the in-memory storage for dead tuple pointers gets full, whose + size is defined by autovacuum_work_mem. So increasing this parameter + can make the operation finish more quickly. This can be monitored with + . + diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 6f82033..6a57688 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -2570,6 +2570,11 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i daemon + last_vacuum_index_scans + integer + Number of splitted index scans performed during the last vacuum or autovacuum on this table + + vacuum_count bigint Number of times this table has been manually vacuumed diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 394aea8..aeba9d5 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -527,6 +527,7 @@ CREATE VIEW pg_stat_all_tables AS pg_stat_get_last_autovacuum_time(C.oid) as last_autovacuum, pg_stat_get_last_analyze_time(C.oid) as last_analyze, pg_stat_get_last_autoanalyze_time(C.oid) as last_autoanalyze, + pg_stat_get_last_vacuum_index_scans(C.oid) AS last_vacuum_index_scans, pg_stat_get_vacuum_count(C.oid) AS vacuum_count, pg_stat_get_autovacuum_count(C.oid) AS autovacuum_count, pg_stat_get_analyze_count(C.oid) AS analyze_count, diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c index 6587db7..c482c8e 100644 --- a/src/backend/commands/vacuumlazy.c +++ b/src/backend/commands/vacuumlazy.c @@ -342,7 +342,8 @@ lazy_vacuum_rel(Relation onerel, int options, VacuumParams *params, pgstat_report_vacuum(RelationGetRelid(onerel), onerel->rd_rel->relisshared, new_live_tuples, - vacrelstats->new_dead_tuples); + vacrelstats->new_dead_tuples, + vacrelstats->num_index_scans); pgstat_progress_end_command(); /* and log the action if appropriate */ diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c index 5c256ff..5f3fdf6 100644 --- a/src/backend/postmaster/pgstat.c +++ b/src/backend/postmaster/pgstat.c @@ -1403,7 +1403,8 @@ pgstat_report_autovac(Oid dboid) */ void pgstat_report_vacuum(Oid tableoid, bool shared, - PgStat_Counter livetuples, PgStat_Counter deadtuples) + PgStat_Counter livetuples, PgStat_Counter deadtuples, + PgStat_Counter num_index_scans) { PgStat_MsgVacuum msg; @@ -1417,6 +1418,7 @@ pgstat_report_vacuum(Oid tableoid, bool shared, msg.m_vacuumtime = GetCurrentTimestamp(); msg.m_live_tuples = livetuples; msg.m_dead_tuples = deadtuples; + msg.m_num_index_scans = num_index_scans; pgstat_send(&msg, sizeof(msg)); } @@ -4585,6 +4587,7 @@ pgstat_get_tab_entry(PgStat_StatDBEntry *dbentry, Oid tableoid, bool create) result->n_live_tuples = 0; result->n_dead_tuples = 0; result->changes_since_analyze = 0; + result->n_index_scans = 0; result->blocks_fetched = 0; result->blocks_hit = 0; result->vacuum_timestamp = 0; @@ -5981,6 +5984,7 @@ pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len) tabentry->n_live_tuples = msg->m_live_tuples; tabentry->n_dead_tuples = msg->m_dead_tuples; + tabentry->n_index_scans = msg->m_num_index_scans; if (msg->m_autovacuum) { diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 8d9e7c1..2956356 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -194,6 +194,20 @@ pg_stat_get_mod_since_analyze(PG_FUNCTION_ARGS) PG_RETURN_INT64(result); } +Datum +pg_stat_get_last_vacuum_index_scans(PG_FUNCTION_ARGS) +{ + Oid relid = PG_GETARG_OID(0); + int32 result; + PgStat_StatTabEntry *tabentry; + + if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL) + result = 0; + else + result = (int32) (tabentry->n_index_scans); + + PG_RETURN_INT32(result); +} Datum pg_stat_get_blocks_fetched(PG_FUNCTION_ARGS) diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h index 0330c04..f3b606b 100644 --- a/src/include/catalog/pg_proc.h +++ b/src/include/catalog/pg_proc.h @@ -2887,6 +2887,8 @@ DATA(insert OID = 3317 ( pg_stat_get_wal_receiver PGNSP PGUID 12 1 0 0 0 f f f DESCR("statistics: information about WAL receiver"); DATA(insert OID = 6118 ( pg_stat_get_subscription PGNSP PGUID 12 1 0 0 0 f f f f f f s r 1 0 2249 "26" "{26,26,26,23,3220,1184,1184,3220,1184}" "{i,o,o,o,o,o,o,o,o}" "{subid,subid,relid,pid,received_lsn,last_msg_send_time,last_msg_receipt_time,latest_end_lsn,latest_end_time}" _null_ _null_ pg_stat_get_subscription _null_ _null_ _null_ )); DESCR("statistics: information about subscription"); +DATA(insert OID = 3281 ( pg_stat_get_last_vacuum_index_scans PGNSP PGUID 12 1 0 0 0 f f f f t f s r 1 0 23 "26" _null_ _null_ _null_ _null_ _null_ pg_stat_get_last_vacuum_index_scans _null_ _null_ _null_ )); +DESCR("statistics: number of index scans in the last vacuum"); DATA(insert OID = 2026 ( pg_backend_pid PGNSP PGUID 12 1 0 0 0 f f f f t f s r 0 0 23 "" _null_ _null_ _null_ _null_ _null_ pg_backend_pid _null_ _null_ _null_ )); DESCR("statistics: current backend PID"); DATA(insert OID = 1937 ( pg_stat_get_backend_pid PGNSP PGUID 12 1 0 0 0 f f f f t f s r 1 0 23 "23" _null_ _null_ _null_ _null_ _null_ pg_stat_get_backend_pid _null_ _null_ _null_ )); diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 089b7c3..3ab5f4a 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -369,6 +369,7 @@ typedef struct PgStat_MsgVacuum TimestampTz m_vacuumtime; PgStat_Counter m_live_tuples; PgStat_Counter m_dead_tuples; + PgStat_Counter m_num_index_scans; } PgStat_MsgVacuum; @@ -629,6 +630,7 @@ typedef struct PgStat_StatTabEntry PgStat_Counter n_live_tuples; PgStat_Counter n_dead_tuples; PgStat_Counter changes_since_analyze; + PgStat_Counter n_index_scans; PgStat_Counter blocks_fetched; PgStat_Counter blocks_hit; @@ -1165,7 +1167,8 @@ extern void pgstat_reset_single_counter(Oid objectid, PgStat_Single_Reset_Type t extern void pgstat_report_autovac(Oid dboid); extern void pgstat_report_vacuum(Oid tableoid, bool shared, - PgStat_Counter livetuples, PgStat_Counter deadtuples); + PgStat_Counter livetuples, PgStat_Counter deadtuples, + PgStat_Counter num_index_scans); extern void pgstat_report_analyze(Relation rel, PgStat_Counter livetuples, PgStat_Counter deadtuples, bool resetcounter); diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index f1c1b44..d0bb46c 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1763,6 +1763,7 @@ pg_stat_all_tables| SELECT c.oid AS relid, pg_stat_get_last_autovacuum_time(c.oid) AS last_autovacuum, pg_stat_get_last_analyze_time(c.oid) AS last_analyze, pg_stat_get_last_autoanalyze_time(c.oid) AS last_autoanalyze, + pg_stat_get_last_vacuum_index_scans(c.oid) AS last_vacuum_index_scans, pg_stat_get_vacuum_count(c.oid) AS vacuum_count, pg_stat_get_autovacuum_count(c.oid) AS autovacuum_count, pg_stat_get_analyze_count(c.oid) AS analyze_count, @@ -1910,6 +1911,7 @@ pg_stat_sys_tables| SELECT pg_stat_all_tables.relid, pg_stat_all_tables.last_autovacuum, pg_stat_all_tables.last_analyze, pg_stat_all_tables.last_autoanalyze, + pg_stat_all_tables.last_vacuum_index_scans, pg_stat_all_tables.vacuum_count, pg_stat_all_tables.autovacuum_count, pg_stat_all_tables.analyze_count, @@ -1953,6 +1955,7 @@ pg_stat_user_tables| SELECT pg_stat_all_tables.relid, pg_stat_all_tables.last_autovacuum, pg_stat_all_tables.last_analyze, pg_stat_all_tables.last_autoanalyze, + pg_stat_all_tables.last_vacuum_index_scans, pg_stat_all_tables.vacuum_count, pg_stat_all_tables.autovacuum_count, pg_stat_all_tables.analyze_count, -- 2.9.2