Hello everyone, This is Ayoub again, I've just changed my email address.
On Sun, Jul 12, 2026 at 11:57 PM David Geier <[email protected]> wrote: > On 29.04.2026 15:45, KAZAR Ayoub wrote: > >>>> The global cache stats is going to be virtually free (at least the > >>>> hits/misses, I'm not sure about the number of entries and bytes), and > >>>> it's obviously useful for tuning the max_files_per_process GUC. I'd > even > >>>> contemplate getting this into PG19, maybe. > >> > >> The number of used entries already exists, see nfile in fd.c. > >> > > Would one want the number of all entries (i.e SizeVfdCache see fd.c) or > the > > number of used entries (i.e entries with fds in use, which is nfile) ? I > > thought of the first, that's what 0002 patch contains for the moment. > > I thought we would expose both. That way we can assess in the field if > being able to shrink the cache would be useful. > Done. > > >> Including the total cache size would also be virtually free if we don't > >> iterate over all VFDs each time, but update the size as we go. That > >> would have to happen when resizing the cache and when populating / > >> freeing a cache entry because extra memory is allocated / freed for > >> Vfd::fileName. > >> > > Is it a big deal if we miss some bytes of filename globally ? > > It's not just some bytes. sizeof(struct vfd) is 56 bytes and fileName > looks typically something like: > > - base/5/1249 > - pg_wal/000000010000000000000001 > - pg_wal/archive_status/000000010000000000000001.ready > - pg_xact/0000 > - pg_multixact/offsets/0000 > > File names can vary in length between 10 - 55 bytes, give or take. Most > files will be table and index segments and WAL files. We could maybe add > a fixed constant as "assumed average file name length" but I'm worried > that might end up being quite wrong. I chose to keep an accurate running count of the memory footprint per backend by tracking both the sizeof(Vfd) and the exact filename string lengths. We add the string length to the total footprint when a file is opened, and subtract it when the VFD is freed (i suppose this is not "Too much" of a work done, although it's done in a bit hot place); v5 of the patch is attached. > > > -- > David Geier > > Regards, Ayoub KAZAR
From 5683435456a7fc5faccc8b4b442fb2dfed756e1f Mon Sep 17 00:00:00 2001 From: AyoubKAZ <[email protected]> Date: Sat, 4 Jul 2026 19:16:16 +0200 Subject: [PATCH 1/2] Add pg_stat_vfdcache view for VFD cache statistics PostgreSQL's virtual file descriptor (VFD) layer maintains a per-backend cache of open file descriptors bounded by max_files_per_process (default 1000). When the cache is full, the least-recently-used entry is evicted (its OS fd closed) so a new file can be opened. A subsequent access to an evicted file must call open() again. A trivial example is with partitioned tables: a table with 1500 partitions requires up to many file descriptors per full scan (main fork, vm ...), which is more than the default limit, causing potential evictions and reopens. This commit adds: pg_stat_vfdcache -- a single-row view exposing cluster-wide VFD cache statistics: hits number of VFD cache hits misses number of VFD cache misses max_open_fds maximum number of file descriptors available to each backend process hit_ratio hits / (hits + misses) stats_reset timestamp of last counter reset pg_stat_reset_vfdcache() -- resets shared VFD counters The implementation follows the same cumulative shared statistics infrastructure like pgstat_bgwriter and others do. Event counting remains cheap in backend-local pending storage and is flushed into shared fixed stats which requires locking. Hit and miss counters are placed in FileAccess(), which is the single gate through which all VFD-mediated file reads, writes, truncations, and size checks pass. --- doc/src/sgml/monitoring.sgml | 107 ++++++++++++++++++ src/backend/catalog/system_views.sql | 16 +++ src/backend/storage/file/fd.c | 5 +- src/backend/utils/activity/Makefile | 1 + src/backend/utils/activity/meson.build | 1 + src/backend/utils/activity/pgstat.c | 17 +++ src/backend/utils/activity/pgstat_vfdcache.c | 113 +++++++++++++++++++ src/backend/utils/adt/pgstatfuncs.c | 47 +++++++- src/include/catalog/pg_proc.dat | 30 +++++ src/include/pgstat.h | 26 +++++ src/include/utils/pgstat_internal.h | 22 +++- src/include/utils/pgstat_kind.h | 3 +- src/test/regress/expected/rules.out | 8 ++ src/test/regress/expected/stats.out | 19 +++- src/test/regress/sql/stats.sql | 5 + 15 files changed, 414 insertions(+), 6 deletions(-) create mode 100644 src/backend/utils/activity/pgstat_vfdcache.c diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 12b9ee20d4a..67acd370215 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -553,6 +553,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser </entry> </row> + <row> + <entry><structname>pg_stat_vfdcache</structname><indexterm><primary>pg_stat_vfdcache</primary></indexterm></entry> + <entry>One row only, showing cluster-wide statistics about virtual file + descriptor (VFD) cache activity. See + <link linkend="monitoring-pg-stat-vfdcache-view"> + <structname>pg_stat_vfdcache</structname></link> for details. + </entry> + </row> + <row> <entry><structname>pg_stat_wal</structname><indexterm><primary>pg_stat_wal</primary></indexterm></entry> <entry>One row only, showing statistics about WAL activity. See @@ -3744,6 +3753,89 @@ description | Waiting for a newly initialized WAL file to reach durable storage </para> </sect2> + <sect2 id="monitoring-pg-stat-vfdcache-view"> + <title><structname>pg_stat_vfdcache</structname></title> + + <indexterm zone="monitoring-pg-stat-vfdcache-view"> + <primary>pg_stat_vfdcache</primary> + </indexterm> + + <para> + The <structname>pg_stat_vfdcache</structname> view will always have a + single row, containing data about cluster-wide VFD (Virtual File + Descriptor) cache activity. + </para> + + <table id="pg-stat-vfdcache-view" xreflabel="pg_stat_vfdcache"> + <title><structname>pg_stat_vfdcache</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>hits</structfield> <type>bigint</type> + </para> + <para> + Number of file accesses where the physical file descriptor was + already open in the cache, requiring no system call + </para></entry> + </row> + + <row> + <entry role="catalog_table_entry"><para role="column_definition"> + <structfield>misses</structfield> <type>bigint</type> + </para> + <para> + Number of file accesses where the physical file descriptor had + been evicted from the cache, requiring <function>open()</function> + to be called again before the access could proceed + </para></entry> + </row> + + <row> + <entry role="catalog_table_entry"><para role="column_definition"> + <structfield>max_open_fds</structfield> <type>integer</type> + </para> + <para> + Maximum number of file descriptors available to each backend process + </para></entry> + </row> + + <row> + <entry role="catalog_table_entry"><para role="column_definition"> + <structfield>hit_ratio</structfield> <type>float8</type> + </para> + <para> + Fraction of file accesses that were cache hits: + <literal>hits / (hits + misses)</literal> + </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 the counters were last reset by + <function>pg_stat_reset_vfdcache()</function> + </para></entry> + </row> + </tbody> + </tgroup> + </table> + + </sect2> + <sect2 id="monitoring-pg-stat-wal-view"> <title><structname>pg_stat_wal</structname></title> @@ -5974,6 +6066,21 @@ description | Waiting for a newly initialized WAL file to reach durable storage can be granted EXECUTE to run the function. </para></entry> </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>pg_stat_reset_vfdcache</primary> + </indexterm> + <function>pg_stat_reset_vfdcache</function> () + <returnvalue>void</returnvalue> + </para> + <para> + Reset shared VFD cache statistics counters to zero. The reset + timestamp is recorded in + <structname>pg_stat_vfdcache</structname>.<structfield>stats_reset</structfield>. + </para></entry> + </row> </tbody> </tgroup> </table> diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 6c1c5545cb5..42a82ecb07d 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -1568,3 +1568,19 @@ CREATE VIEW pg_aios AS SELECT * FROM pg_get_aios(); REVOKE ALL ON pg_aios FROM PUBLIC; GRANT SELECT ON pg_aios TO pg_read_all_stats; + +CREATE VIEW pg_stat_vfdcache AS + SELECT + pg_stat_get_vfd_hits() AS hits, + pg_stat_get_vfd_misses() AS misses, + pg_stat_get_vfd_max_open_fds() AS max_open_fds, + CASE + WHEN pg_stat_get_vfd_hits() + pg_stat_get_vfd_misses() = 0 + THEN NULL::float8 + ELSE pg_stat_get_vfd_hits()::float8 + / (pg_stat_get_vfd_hits() + pg_stat_get_vfd_misses()) + END AS hit_ratio, + pg_stat_get_vfd_stat_reset_time() AS stats_reset; + +REVOKE ALL ON pg_stat_vfdcache FROM PUBLIC; +GRANT SELECT ON pg_stat_vfdcache TO PUBLIC; diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c index 4cf4717f764..4954e639397 100644 --- a/src/backend/storage/file/fd.c +++ b/src/backend/storage/file/fd.c @@ -1480,6 +1480,7 @@ static int FileAccess(File file) { int returnValue; + bool is_open; DO_DB(elog(LOG, "FileAccess %d (%s)", file, VfdCache[file].fileName)); @@ -1488,8 +1489,10 @@ FileAccess(File file) * Is the file open? If not, open it and put it at the head of the LRU * ring (possibly closing the least recently used file to get an FD). */ + is_open = !FileIsNotOpen(file); + pgstat_count_vfd_access(is_open); - if (FileIsNotOpen(file)) + if (!is_open) { returnValue = LruInsert(file); if (returnValue != 0) diff --git a/src/backend/utils/activity/Makefile b/src/backend/utils/activity/Makefile index 5fed953c28a..b14d46998f9 100644 --- a/src/backend/utils/activity/Makefile +++ b/src/backend/utils/activity/Makefile @@ -33,6 +33,7 @@ OBJS = \ pgstat_shmem.o \ pgstat_slru.o \ pgstat_subscription.o \ + pgstat_vfdcache.o \ pgstat_wal.o \ pgstat_xact.o \ wait_event.o \ diff --git a/src/backend/utils/activity/meson.build b/src/backend/utils/activity/meson.build index 470b5dac402..4cd7bb9fb64 100644 --- a/src/backend/utils/activity/meson.build +++ b/src/backend/utils/activity/meson.build @@ -18,6 +18,7 @@ backend_sources += files( 'pgstat_shmem.c', 'pgstat_slru.c', 'pgstat_subscription.c', + 'pgstat_vfdcache.c', 'pgstat_wal.c', 'pgstat_xact.c', ) diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c index c4fa14f138f..b4c7113381f 100644 --- a/src/backend/utils/activity/pgstat.c +++ b/src/backend/utils/activity/pgstat.c @@ -500,6 +500,23 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .reset_all_cb = pgstat_wal_reset_all_cb, .snapshot_cb = pgstat_wal_snapshot_cb, }, + + [PGSTAT_KIND_VFDCACHE] = { + .name = "vfdcache", + + .fixed_amount = true, + .write_to_file = true, + + .snapshot_ctl_off = offsetof(PgStat_Snapshot, vfdcache), + .shared_ctl_off = offsetof(PgStat_ShmemControl, vfdcache), + .shared_data_off = offsetof(PgStatShared_VfdCache, stats), + .shared_data_len = sizeof(((PgStatShared_VfdCache *) 0)->stats), + + .flush_static_cb = pgstat_vfdcache_flush_cb, + .init_shmem_cb = pgstat_vfdcache_init_shmem_cb, + .reset_all_cb = pgstat_vfdcache_reset_all_cb, + .snapshot_cb = pgstat_vfdcache_snapshot_cb, + }, }; /* diff --git a/src/backend/utils/activity/pgstat_vfdcache.c b/src/backend/utils/activity/pgstat_vfdcache.c new file mode 100644 index 00000000000..b036759031c --- /dev/null +++ b/src/backend/utils/activity/pgstat_vfdcache.c @@ -0,0 +1,113 @@ +/* ------------------------------------------------------------------------- + * + * pgstat_vfdcache.c + * Implementation of VFD cache statistics. + * + * VFD events are first counted in backend-local pending storage and then + * flushed into shared-memory cumulative stats, following the same model as + * other fixed stats kinds. + * + * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group + * + * IDENTIFICATION + * src/backend/utils/activity/pgstat_vfdcache.c + * ------------------------------------------------------------------------- + */ + +#include "postgres.h" + +#include "pgstat.h" +#include "utils/memutils.h" +#include "utils/pgstat_internal.h" + +/* + * Backend-local VFD counters waiting to be flushed. + */ +PgStat_VfdCacheStats PendingVfdCacheStats = {0}; + +/* + * Count a VFD cache access as either a hit or miss. + */ +void +pgstat_count_vfd_access(bool hit) +{ + if (hit) + PendingVfdCacheStats.vfd_hits++; + else + PendingVfdCacheStats.vfd_misses++; + pgstat_report_fixed = true; +} + +/* + * Flush out backend-local pending VFD cache stats. + */ +bool +pgstat_vfdcache_flush_cb(bool nowait) +{ + PgStatShared_VfdCache *stats_shmem = &pgStatLocal.shmem->vfdcache; + + if (pg_memory_is_all_zeros(&PendingVfdCacheStats, + sizeof(struct PgStat_VfdCacheStats))) + return false; + + if (!nowait) + LWLockAcquire(&stats_shmem->lock, LW_EXCLUSIVE); + else if (!LWLockConditionalAcquire(&stats_shmem->lock, LW_EXCLUSIVE)) + return true; + + stats_shmem->stats.vfd_hits += PendingVfdCacheStats.vfd_hits; + stats_shmem->stats.vfd_misses += PendingVfdCacheStats.vfd_misses; + + LWLockRelease(&stats_shmem->lock); + + MemSet(&PendingVfdCacheStats, 0, sizeof(PendingVfdCacheStats)); + + return false; +} + +/* + * Support function for SQL-callable pg_stat_get_vfd_* functions. + */ +PgStat_VfdCacheStats * +pgstat_fetch_stat_vfdcache(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_VFDCACHE); + + return &pgStatLocal.snapshot.vfdcache; +} + +void +pgstat_vfdcache_init_shmem_cb(void *stats) +{ + PgStatShared_VfdCache *stats_shmem = (PgStatShared_VfdCache *) stats; + + LWLockInitialize(&stats_shmem->lock, LWTRANCHE_PGSTATS_DATA); +} + +void +pgstat_vfdcache_reset_all_cb(TimestampTz ts) +{ + PgStatShared_VfdCache *stats_shmem = &pgStatLocal.shmem->vfdcache; + + LWLockAcquire(&stats_shmem->lock, LW_EXCLUSIVE); + MemSet(&stats_shmem->stats, 0, sizeof(stats_shmem->stats)); + stats_shmem->stats.stat_reset_timestamp = ts; + LWLockRelease(&stats_shmem->lock); +} + +void +pgstat_vfdcache_snapshot_cb(void) +{ + PgStatShared_VfdCache *stats_shmem = &pgStatLocal.shmem->vfdcache; + + LWLockAcquire(&stats_shmem->lock, LW_SHARED); + memcpy(&pgStatLocal.snapshot.vfdcache, &stats_shmem->stats, + sizeof(pgStatLocal.snapshot.vfdcache)); + LWLockRelease(&stats_shmem->lock); +} + +void +pgstat_reset_vfdcache(void) +{ + pgstat_reset_of_kind(PGSTAT_KIND_VFDCACHE); +} diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 565d0e70768..714918d292c 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -26,6 +26,7 @@ #include "pgstat.h" #include "postmaster/bgworker.h" #include "replication/logicallauncher.h" +#include "storage/fd.h" #include "storage/proc.h" #include "storage/procarray.h" #include "utils/acl.h" @@ -1336,6 +1337,47 @@ pg_stat_get_buf_alloc(PG_FUNCTION_ARGS) PG_RETURN_INT64(pgstat_fetch_stat_bgwriter()->buf_alloc); } +Datum +pg_stat_get_vfd_hits(PG_FUNCTION_ARGS) +{ + PG_RETURN_INT64(pgstat_fetch_stat_vfdcache()->vfd_hits); +} + +Datum +pg_stat_get_vfd_misses(PG_FUNCTION_ARGS) +{ + PG_RETURN_INT64(pgstat_fetch_stat_vfdcache()->vfd_misses); +} + +Datum +pg_stat_get_vfd_max_open_fds(PG_FUNCTION_ARGS) +{ + PG_RETURN_INT32(max_safe_fds); +} + +Datum +pg_stat_get_vfd_stat_reset_time(PG_FUNCTION_ARGS) +{ + TimestampTz ts = pgstat_fetch_stat_vfdcache()->stat_reset_timestamp; + + if (ts == 0) + PG_RETURN_NULL(); + + PG_RETURN_TIMESTAMPTZ(ts); +} + +/* + * pg_stat_reset_vfdcache + * Reset shared VFD cache counters. + */ +Datum +pg_stat_reset_vfdcache(PG_FUNCTION_ARGS) +{ + pgstat_reset_vfdcache(); + PG_RETURN_VOID(); +} + + /* * When adding a new column to the pg_stat_io view and the * pg_stat_get_backend_io() function, add a new enum value here above @@ -2001,6 +2043,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); + pgstat_reset_of_kind(PGSTAT_KIND_VFDCACHE); PG_RETURN_VOID(); } @@ -2021,13 +2064,15 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) pgstat_reset_of_kind(PGSTAT_KIND_SLRU); + else if (strcmp(target, "vfdcache") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_VFDCACHE); else if (strcmp(target, "wal") == 0) pgstat_reset_of_kind(PGSTAT_KIND_WAL); else ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("unrecognized reset target: \"%s\"", target), - errhint("Target must be \"archiver\", \"bgwriter\", \"checkpointer\", \"io\", \"lock\", \"recovery_prefetch\", \"slru\", or \"wal\"."))); + errhint("Target must be \"archiver\", \"bgwriter\", \"checkpointer\", \"io\", \"lock\", \"recovery_prefetch\", \"slru\", \"vfdcache\", or \"wal\"."))); PG_RETURN_VOID(); } diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 3cb84359adf..52a9579f873 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -12717,5 +12717,35 @@ { oid => '6462', descr => 'hash', proname => 'hashoid8extended', prorettype => 'int8', proargtypes => 'oid8 int8', prosrc => 'hashoid8extended' }, +{ oid => '9560', + descr => 'statistics: number of VFD cache hits', + proname => 'pg_stat_get_vfd_hits', + provolatile => 'v', proparallel => 'r', + prorettype => 'int8', proargtypes => '', + prosrc => 'pg_stat_get_vfd_hits' }, +{ oid => '9561', + descr => 'statistics: number of VFD cache misses', + proname => 'pg_stat_get_vfd_misses', + provolatile => 'v', proparallel => 'r', + prorettype => 'int8', proargtypes => '', + prosrc => 'pg_stat_get_vfd_misses' }, +{ oid => '9564', + descr => 'statistics: timestamp of last VFD cache stats reset', + proname => 'pg_stat_get_vfd_stat_reset_time', + provolatile => 'v', proparallel => 'r', + prorettype => 'timestamptz', proargtypes => '', + prosrc => 'pg_stat_get_vfd_stat_reset_time' }, +{ oid => '9565', + descr => 'statistics: reset shared VFD cache counters', + proname => 'pg_stat_reset_vfdcache', + provolatile => 'v', proparallel => 'r', + prorettype => 'void', proargtypes => '', + prosrc => 'pg_stat_reset_vfdcache' }, +{ oid => '9566', + descr => 'statistics: max number of file descriptors available to backend', + proname => 'pg_stat_get_vfd_max_open_fds', + provolatile => 'v', proparallel => 'r', + prorettype => 'int4', proargtypes => '', + prosrc => 'pg_stat_get_vfd_max_open_fds' }, ] diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 58a44857f13..5791894782b 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -272,6 +272,19 @@ typedef struct PgStat_CheckpointerStats TimestampTz stat_reset_timestamp; } PgStat_CheckpointerStats; +/* --------- + * PgStat_VfdCacheStats Virtual File Descriptor cache statistics + * + * Tracks hit/miss events in the VFD cache (fd.c). These counters + * are accumulated in shared fixed stats and exposed by pg_stat_vfdcache. + * --------- + */ +typedef struct PgStat_VfdCacheStats +{ + PgStat_Counter vfd_hits; /* fd was open, no open() was needed */ + PgStat_Counter vfd_misses; /* fd was VFD_CLOSED, open() was required */ + TimestampTz stat_reset_timestamp; +} PgStat_VfdCacheStats; /* * Types related to counting IO operations @@ -619,6 +632,13 @@ extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void); extern void pgstat_report_checkpointer(void); extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void); +/* + * Functions in pgstat_vfdcache.c + */ + +extern PgStat_VfdCacheStats *pgstat_fetch_stat_vfdcache(void); +extern void pgstat_reset_vfdcache(void); +extern void pgstat_count_vfd_access(bool hit); /* * Functions in pgstat_io.c @@ -861,6 +881,12 @@ extern PGDLLIMPORT int pgstat_fetch_consistency; /* updated directly by bgwriter and bufmgr */ extern PGDLLIMPORT PgStat_BgWriterStats PendingBgWriterStats; +/* + * Variables in pgstat_vfdcache.c + */ + +/* updated by VFD counting functions called from fd.c */ +extern PGDLLIMPORT PgStat_VfdCacheStats PendingVfdCacheStats; /* * Variables in pgstat_checkpointer.c diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h index b3dc3ff7d8b..790de4436d9 100644 --- a/src/include/utils/pgstat_internal.h +++ b/src/include/utils/pgstat_internal.h @@ -296,7 +296,7 @@ typedef struct PgStat_KindInfo /* * For variable-numbered stats: flush pending stats. Required if pending * data is used. See flush_static_cb when dealing with stats data that - * that cannot use PgStat_EntryRef->pending. + * cannot use PgStat_EntryRef->pending. */ bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait); @@ -485,6 +485,13 @@ typedef struct PgStatShared_Wal PgStat_WalStats stats; } PgStatShared_Wal; +typedef struct PgStatShared_VfdCache +{ + /* lock protects ->stats */ + LWLock lock; + PgStat_VfdCacheStats stats; +} PgStatShared_VfdCache; + /* ---------- @@ -580,6 +587,7 @@ typedef struct PgStat_ShmemControl PgStatShared_Lock lock; PgStatShared_SLRU slru; PgStatShared_Wal wal; + PgStatShared_VfdCache vfdcache; /* * Custom stats data with fixed-numbered objects, indexed by (PgStat_Kind @@ -616,6 +624,8 @@ typedef struct PgStat_Snapshot PgStat_WalStats wal; + PgStat_VfdCacheStats vfdcache; + /* * Data in snapshot for custom fixed-numbered statistics, indexed by * (PgStat_Kind - PGSTAT_KIND_CUSTOM_MIN). Each entry is allocated in @@ -731,6 +741,16 @@ extern void pgstat_checkpointer_reset_all_cb(TimestampTz ts); extern void pgstat_checkpointer_snapshot_cb(void); +/* + * Functions in pgstat_vfdcache.c + */ + +extern bool pgstat_vfdcache_flush_cb(bool nowait); +extern void pgstat_vfdcache_init_shmem_cb(void *stats); +extern void pgstat_vfdcache_reset_all_cb(TimestampTz ts); +extern void pgstat_vfdcache_snapshot_cb(void); + + /* * Functions in pgstat_database.c */ diff --git a/src/include/utils/pgstat_kind.h b/src/include/utils/pgstat_kind.h index 2d78a029683..319ec0bd63b 100644 --- a/src/include/utils/pgstat_kind.h +++ b/src/include/utils/pgstat_kind.h @@ -39,9 +39,10 @@ #define PGSTAT_KIND_LOCK 11 #define PGSTAT_KIND_SLRU 12 #define PGSTAT_KIND_WAL 13 +#define PGSTAT_KIND_VFDCACHE 14 #define PGSTAT_KIND_BUILTIN_MIN PGSTAT_KIND_DATABASE -#define PGSTAT_KIND_BUILTIN_MAX PGSTAT_KIND_WAL +#define PGSTAT_KIND_BUILTIN_MAX PGSTAT_KIND_VFDCACHE #define PGSTAT_KIND_BUILTIN_SIZE (PGSTAT_KIND_BUILTIN_MAX + 1) /* Custom stats kinds */ diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 39905c2de14..d195291a27a 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -2423,6 +2423,14 @@ pg_stat_user_tables| SELECT relid, stats_reset FROM pg_stat_all_tables WHERE ((schemaname <> ALL (ARRAY['pg_catalog'::name, 'information_schema'::name])) AND (schemaname !~ '^pg_toast'::text)); +pg_stat_vfdcache| SELECT pg_stat_get_vfd_hits() AS hits, + pg_stat_get_vfd_misses() AS misses, + pg_stat_get_vfd_max_open_fds() AS max_open_fds, + CASE + WHEN ((pg_stat_get_vfd_hits() + pg_stat_get_vfd_misses()) = 0) THEN NULL::double precision + ELSE ((pg_stat_get_vfd_hits())::double precision / ((pg_stat_get_vfd_hits() + pg_stat_get_vfd_misses()))::double precision) + END AS hit_ratio, + pg_stat_get_vfd_stat_reset_time() AS stats_reset; pg_stat_wal| SELECT wal_records, wal_fpi, wal_bytes, diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index 03cbc1cdef5..8b88fba4540 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -134,7 +134,8 @@ SELECT id, name, fixed_amount, 11 | lock | t | f | t 12 | slru | t | f | t 13 | wal | t | f | t -(13 rows) + 14 | vfdcache | t | f | t +(14 rows) -- ensure that both seqscan and indexscan plans are allowed SET enable_seqscan TO on; @@ -1184,10 +1185,24 @@ SELECT stats_reset > :'wal_reset_ts'::timestamptz FROM pg_stat_wal; t (1 row) +-- Test that reset_shared with vfdcache specified as the stats type works +SELECT stats_reset AS vfdcache_reset_ts FROM pg_stat_vfdcache \gset +SELECT pg_stat_reset_shared('vfdcache'); + pg_stat_reset_shared +---------------------- + +(1 row) + +SELECT stats_reset > :'vfdcache_reset_ts'::timestamptz FROM pg_stat_vfdcache; + ?column? +---------- + t +(1 row) + -- Test error case for reset_shared with unknown stats type SELECT pg_stat_reset_shared('unknown'); ERROR: unrecognized reset target: "unknown" -HINT: Target must be "archiver", "bgwriter", "checkpointer", "io", "lock", "recovery_prefetch", "slru", or "wal". +HINT: Target must be "archiver", "bgwriter", "checkpointer", "io", "lock", "recovery_prefetch", "slru", "vfdcache", or "wal". -- Test that reset works for pg_stat_database and pg_stat_database_conflicts -- Since pg_stat_database stats_reset starts out as NULL, reset it once first so that we -- have a baseline for comparison. The same for pg_stat_database_conflicts as it shares diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 4c265d1245c..1247731c4d1 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -535,6 +535,11 @@ SELECT stats_reset AS wal_reset_ts FROM pg_stat_wal \gset SELECT pg_stat_reset_shared('wal'); SELECT stats_reset > :'wal_reset_ts'::timestamptz FROM pg_stat_wal; +-- Test that reset_shared with vfdcache specified as the stats type works +SELECT stats_reset AS vfdcache_reset_ts FROM pg_stat_vfdcache \gset +SELECT pg_stat_reset_shared('vfdcache'); +SELECT stats_reset > :'vfdcache_reset_ts'::timestamptz FROM pg_stat_vfdcache; + -- Test error case for reset_shared with unknown stats type SELECT pg_stat_reset_shared('unknown'); -- 2.34.1
From 37de112185d8d444f06d55a09837885d7fa24090 Mon Sep 17 00:00:00 2001 From: AyoubKAZ <[email protected]> Date: Sat, 4 Jul 2026 19:39:25 +0200 Subject: [PATCH 2/2] Add VFD cache footprint metrics to pg_stat_vfdcache Extend pg_stat_vfdcache with three additional columns: open_entries number of currently open file descriptors inside VFD cache allocated_entries total number of allocated slots in the cache cache_bytes total memory used by VFD cache, including sizeof(Vfd) for allocated slots and the heap-allocated fileName strings These are live gauges. Each backend publishes its current VFD cache footprint into backend shared stats during backend stats flush, and SQL accessors sum those backend shared stats entries to produce cluster-wide totals. The memory footprint is computed incrementally inside fd.c using a running counter, avoiding expensive iterations or averages, and accurately accounting for filename string allocations. --- doc/src/sgml/monitoring.sgml | 33 ++++++++ src/backend/catalog/system_views.sql | 3 + src/backend/storage/file/fd.c | 48 ++++++++++- src/backend/utils/activity/pgstat_backend.c | 52 ++++++++++++ src/backend/utils/adt/pgstatfuncs.c | 93 +++++++++++++++++++++ src/include/catalog/pg_proc.dat | 18 ++++ src/include/pgstat.h | 15 ++++ src/include/storage/fd.h | 3 + src/include/utils/pgstat_internal.h | 6 +- src/test/regress/expected/rules.out | 3 + 10 files changed, 272 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 67acd370215..1d63d17a2b8 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -3802,6 +3802,39 @@ description | Waiting for a newly initialized WAL file to reach durable storage </para></entry> </row> + <row> + <entry role="catalog_table_entry"><para role="column_definition"> + <structfield>open_entries</structfield> <type>bigint</type> + </para> + <para> + Sum of VFD slots currently holding an open kernel file descriptor + across all active backends (equivalent to summing each backend's + <literal>nfile</literal> counter) + </para></entry> + </row> + + <row> + <entry role="catalog_table_entry"><para role="column_definition"> + <structfield>allocated_entries</structfield> <type>bigint</type> + </para> + <para> + Sum of allocated VFD cache entries across all active backends, + including entries whose file descriptor has been closed by the LRU + eviction policy but whose slot has not yet been freed + </para></entry> + </row> + + <row> + <entry role="catalog_table_entry"><para role="column_definition"> + <structfield>cache_bytes</structfield> <type>bigint</type> + </para> + <para> + Sum of memory used by VFD cache entries across all active backends, + in bytes; includes <literal>sizeof(Vfd)</literal> for each allocated + slot plus the heap-allocated file name string for each populated slot + </para></entry> + </row> + <row> <entry role="catalog_table_entry"><para role="column_definition"> <structfield>max_open_fds</structfield> <type>integer</type> diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 42a82ecb07d..712542d0fdd 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -1573,6 +1573,9 @@ CREATE VIEW pg_stat_vfdcache AS SELECT pg_stat_get_vfd_hits() AS hits, pg_stat_get_vfd_misses() AS misses, + pg_stat_get_vfd_cache_open_entries() AS open_entries, + pg_stat_get_vfd_cache_allocated_entries() AS allocated_entries, + pg_stat_get_vfd_cache_bytes() AS cache_bytes, pg_stat_get_vfd_max_open_fds() AS max_open_fds, CASE WHEN pg_stat_get_vfd_hits() + pg_stat_get_vfd_misses() = 0 diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c index 4954e639397..80f0a695011 100644 --- a/src/backend/storage/file/fd.c +++ b/src/backend/storage/file/fd.c @@ -225,6 +225,14 @@ static Size SizeVfdCache = 0; */ static int nfile = 0; +/* + * Running total of memory used by the VFD cache for this backend, + * including sizeof(Vfd) for each allocated slot plus the malloc'd + * fileName string for each populated slot. Updated incrementally in + * AllocateVfd(), PathNameOpenFilePerm(), and FreeVfd(). + */ +static uint64 VfdCacheFootprintBytes = 0; + /* * Flag to tell whether it's worth scanning VfdCache looking for temp files * to close @@ -1444,8 +1452,10 @@ AllocateVfd(void) VfdCache[0].nextFree = SizeVfdCache; /* - * Record the new size + * Record the new size and account for the newly allocated Vfd + * structs. */ + VfdCacheFootprintBytes += (newCacheSize - SizeVfdCache) * sizeof(Vfd); SizeVfdCache = newCacheSize; } @@ -1466,6 +1476,7 @@ FreeVfd(File file) if (vfdP->fileName != NULL) { + VfdCacheFootprintBytes -= strlen(vfdP->fileName) + 1; free(vfdP->fileName); vfdP->fileName = NULL; } @@ -1512,6 +1523,40 @@ FileAccess(File file) return 0; } +/* + * Return the number of VFD slots currently holding an open file descriptor. + * This is the nfile counter, which tracks FDs actually open in the kernel. + */ +uint64 +GetVfdCacheOpenEntries(void) +{ + return (uint64) nfile; +} + +/* + * Return the number of currently allocated VFD entries for this backend, + * excluding slot 0 which is used as freelist/LRU header. + */ +uint64 +GetVfdCacheAllocatedEntries(void) +{ + if (SizeVfdCache == 0) + return 0; + + return (uint64) (SizeVfdCache - 1); +} + +/* + * Return the current memory footprint of the VFD cache for this backend. + * This includes sizeof(Vfd) for each allocated slot and the malloc'd + * fileName bytes for each currently-populated slot. + */ +uint64 +GetVfdCacheBytes(void) +{ + return VfdCacheFootprintBytes; +} + /* * Called whenever a temporary file is deleted to report its size. */ @@ -1624,6 +1669,7 @@ PathNameOpenFilePerm(const char *fileName, int fileFlags, mode_t fileMode) vfdP->fd)); vfdP->fileName = fnamecopy; + VfdCacheFootprintBytes += strlen(fnamecopy) + 1; /* Saved flags are adjusted to be OK for re-opening file */ vfdP->fileFlags = fileFlags & ~(O_CREAT | O_TRUNC | O_EXCL); vfdP->fileMode = fileMode; diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index b736b2ccc6f..a493b559911 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -27,6 +27,7 @@ #include "access/xlog.h" #include "executor/instrument.h" #include "storage/bufmgr.h" +#include "storage/fd.h" #include "storage/proc.h" #include "storage/procarray.h" #include "utils/memutils.h" @@ -49,6 +50,12 @@ static bool backend_has_lockstats = false; */ static WalUsage prevBackendWalUsage; +/* + * Last per-backend VFD cache gauges published to backend stats. + * Used to detect whether anything changed since the last flush. + */ +static PgStat_BackendVfdCacheStats prevBackendVfdCacheStats; + /* * Utility routines to report I/O stats for backends, kept here to avoid * exposing PendingBackendStats to the outside world. @@ -253,6 +260,21 @@ pgstat_backend_wal_have_pending(void) return (pgWalUsage.wal_records != prevBackendWalUsage.wal_records); } +/* + * Determine whether VFD cache gauges have changed since the last flush. + */ +static inline bool +pgstat_backend_vfdcache_have_pending(void) +{ + PgStat_Counter cur_open = (PgStat_Counter) GetVfdCacheOpenEntries(); + PgStat_Counter cur_alloc = (PgStat_Counter) GetVfdCacheAllocatedEntries(); + PgStat_Counter cur_bytes = (PgStat_Counter) GetVfdCacheBytes(); + + return cur_open != prevBackendVfdCacheStats.open_entries || + cur_alloc != prevBackendVfdCacheStats.allocated_entries || + cur_bytes != prevBackendVfdCacheStats.cache_bytes; +} + /* * Flush out locally pending backend WAL statistics. Locking is managed * by the caller. @@ -326,6 +348,27 @@ pgstat_flush_backend_entry_lock(PgStat_EntryRef *entry_ref) backend_has_lockstats = false; } +/* + * Flush out locally pending backend VFD cache gauges. Locking is managed + * by the caller. No need to check for pending data here; the caller does + * that before acquiring the lock. + */ +static void +pgstat_flush_backend_entry_vfdcache(PgStat_EntryRef *entry_ref) +{ + PgStatShared_Backend *shbackendent; + PgStat_BackendVfdCacheStats *bktype_shstats; + + shbackendent = (PgStatShared_Backend *) entry_ref->shared_stats; + bktype_shstats = &shbackendent->stats.vfdcache_stats; + + bktype_shstats->open_entries = (PgStat_Counter) GetVfdCacheOpenEntries(); + bktype_shstats->allocated_entries = (PgStat_Counter) GetVfdCacheAllocatedEntries(); + bktype_shstats->cache_bytes = (PgStat_Counter) GetVfdCacheBytes(); + + prevBackendVfdCacheStats = *bktype_shstats; +} + /* * Flush out locally pending backend statistics * @@ -354,6 +397,11 @@ pgstat_flush_backend(bool nowait, uint32 flags) if ((flags & PGSTAT_BACKEND_FLUSH_LOCK) && backend_has_lockstats) has_pending_data = true; + /* Some VFD cache data pending? */ + if ((flags & PGSTAT_BACKEND_FLUSH_VFDCACHE) && + pgstat_backend_vfdcache_have_pending()) + has_pending_data = true; + if (!has_pending_data) return false; @@ -372,6 +420,9 @@ pgstat_flush_backend(bool nowait, uint32 flags) if (flags & PGSTAT_BACKEND_FLUSH_LOCK) pgstat_flush_backend_entry_lock(entry_ref); + if (flags & PGSTAT_BACKEND_FLUSH_VFDCACHE) + pgstat_flush_backend_entry_vfdcache(entry_ref); + pgstat_unlock_entry(entry_ref); return false; @@ -411,6 +462,7 @@ pgstat_create_backend(ProcNumber procnum) MemSet(&PendingBackendStats, 0, sizeof(PgStat_BackendPending)); backend_has_iostats = false; backend_has_lockstats = false; + MemSet(&prevBackendVfdCacheStats, 0, sizeof(prevBackendVfdCacheStats)); /* * Initialize prevBackendWalUsage with pgWalUsage so that diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 714918d292c..55835645bae 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -15,6 +15,7 @@ #include "postgres.h" #include "access/htup_details.h" +#include "access/xact.h" #include "access/xlog.h" #include "access/xlogprefetcher.h" #include "catalog/catalog.h" @@ -1349,6 +1350,98 @@ pg_stat_get_vfd_misses(PG_FUNCTION_ARGS) PG_RETURN_INT64(pgstat_fetch_stat_vfdcache()->vfd_misses); } +/* + * Sum per-backend VFD cache gauges across all currently active backends. + * Results are cached for the duration of the current SQL statement to + * avoid redundant scans when the view calls multiple getter functions. + */ +static void +pgstat_get_vfd_backend_sums(PgStat_Counter *open_sum, + PgStat_Counter *alloc_sum, + PgStat_Counter *bytes_sum) +{ + static TimestampTz cached_stmt_start_ts = 0; + static PgStat_Counter cached_open_sum = 0; + static PgStat_Counter cached_alloc_sum = 0; + static PgStat_Counter cached_bytes_sum = 0; + TimestampTz stmt_start_ts = GetCurrentStatementStartTimestamp(); + int num_backends = pgstat_fetch_stat_numbackends(); + + if (cached_stmt_start_ts == stmt_start_ts) + { + *open_sum = cached_open_sum; + *alloc_sum = cached_alloc_sum; + *bytes_sum = cached_bytes_sum; + return; + } + + *open_sum = 0; + *alloc_sum = 0; + *bytes_sum = 0; + + for (int curr_backend = 1; curr_backend <= num_backends; curr_backend++) + { + LocalPgBackendStatus *local_beentry; + PgBackendStatus *beentry; + PgStat_Backend *backend_stats; + + local_beentry = pgstat_get_local_beentry_by_index(curr_backend); + beentry = &local_beentry->backendStatus; + + if (!pgstat_tracks_backend_bktype(beentry->st_backendType)) + continue; + + backend_stats = pgstat_fetch_stat_backend(local_beentry->proc_number); + if (!backend_stats) + continue; + + *open_sum += backend_stats->vfdcache_stats.open_entries; + *alloc_sum += backend_stats->vfdcache_stats.allocated_entries; + *bytes_sum += backend_stats->vfdcache_stats.cache_bytes; + } + + cached_open_sum = *open_sum; + cached_alloc_sum = *alloc_sum; + cached_bytes_sum = *bytes_sum; + cached_stmt_start_ts = stmt_start_ts; +} + +Datum +pg_stat_get_vfd_cache_open_entries(PG_FUNCTION_ARGS) +{ + PgStat_Counter open_sum; + PgStat_Counter alloc_sum; + PgStat_Counter bytes_sum; + + pgstat_get_vfd_backend_sums(&open_sum, &alloc_sum, &bytes_sum); + + PG_RETURN_INT64(open_sum); +} + +Datum +pg_stat_get_vfd_cache_allocated_entries(PG_FUNCTION_ARGS) +{ + PgStat_Counter open_sum; + PgStat_Counter alloc_sum; + PgStat_Counter bytes_sum; + + pgstat_get_vfd_backend_sums(&open_sum, &alloc_sum, &bytes_sum); + + PG_RETURN_INT64(alloc_sum); +} + +Datum +pg_stat_get_vfd_cache_bytes(PG_FUNCTION_ARGS) +{ + PgStat_Counter open_sum; + PgStat_Counter alloc_sum; + PgStat_Counter bytes_sum; + + pgstat_get_vfd_backend_sums(&open_sum, &alloc_sum, &bytes_sum); + + PG_RETURN_INT64(bytes_sum); +} + Datum pg_stat_get_vfd_max_open_fds(PG_FUNCTION_ARGS) { diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 52a9579f873..9435286a171 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -12747,5 +12747,23 @@ provolatile => 'v', proparallel => 'r', prorettype => 'int4', proargtypes => '', prosrc => 'pg_stat_get_vfd_max_open_fds' }, +{ oid => '9562', + descr => 'statistics: number of VFD slots with an open file descriptor across backends', + proname => 'pg_stat_get_vfd_cache_open_entries', + provolatile => 'v', proparallel => 'r', + prorettype => 'int8', proargtypes => '', + prosrc => 'pg_stat_get_vfd_cache_open_entries' }, +{ oid => '9563', + descr => 'statistics: total number of allocated VFD cache entries across backends', + proname => 'pg_stat_get_vfd_cache_allocated_entries', + provolatile => 'v', proparallel => 'r', + prorettype => 'int8', proargtypes => '', + prosrc => 'pg_stat_get_vfd_cache_allocated_entries' }, +{ oid => '9567', + descr => 'statistics: total memory footprint of VFD cache across backends in bytes', + proname => 'pg_stat_get_vfd_cache_bytes', + provolatile => 'v', proparallel => 'r', + prorettype => 'int8', proargtypes => '', + prosrc => 'pg_stat_get_vfd_cache_bytes' }, ] diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 5791894782b..7c7a18c22bb 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -286,6 +286,20 @@ typedef struct PgStat_VfdCacheStats TimestampTz stat_reset_timestamp; } PgStat_VfdCacheStats; +/* ------- + * PgStat_BackendVfdCacheStats Per-backend VFD cache gauges + * + * These are live gauges (not cumulative counters) snapshotted from each + * backend's fd.c variables during stats flush. + * ------- + */ +typedef struct PgStat_BackendVfdCacheStats +{ + PgStat_Counter open_entries; /* FDs currently open (= nfile) */ + PgStat_Counter allocated_entries; /* total allocated VFD slots */ + PgStat_Counter cache_bytes; /* memory footprint in bytes */ +} PgStat_BackendVfdCacheStats; + /* * Types related to counting IO operations */ @@ -537,6 +551,7 @@ typedef struct PgStat_Backend PgStat_BktypeIO io_stats; PgStat_WalCounters wal_counters; PgStat_PendingLock lock_stats; + PgStat_BackendVfdCacheStats vfdcache_stats; } PgStat_Backend; /* --------- diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h index 8ac466fd346..672e18ca19e 100644 --- a/src/include/storage/fd.h +++ b/src/include/storage/fd.h @@ -149,6 +149,9 @@ extern char *FilePathName(File file); extern int FileGetRawDesc(File file); extern int FileGetRawFlags(File file); extern mode_t FileGetRawMode(File file); +extern uint64 GetVfdCacheOpenEntries(void); +extern uint64 GetVfdCacheAllocatedEntries(void); +extern uint64 GetVfdCacheBytes(void); /* Operations used for sharing named temporary files */ extern File PathNameCreateTemporaryFile(const char *path, bool error_on_failure); diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h index 790de4436d9..eb64a96af20 100644 --- a/src/include/utils/pgstat_internal.h +++ b/src/include/utils/pgstat_internal.h @@ -716,7 +716,11 @@ extern void pgstat_archiver_snapshot_cb(void); #define PGSTAT_BACKEND_FLUSH_IO (1 << 0) /* Flush I/O statistics */ #define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */ #define PGSTAT_BACKEND_FLUSH_LOCK (1 << 2) /* Flush lock statistics */ -#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL | PGSTAT_BACKEND_FLUSH_LOCK) +#define PGSTAT_BACKEND_FLUSH_VFDCACHE (1 << 3) /* Flush VFD cache gauges */ +#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | \ + PGSTAT_BACKEND_FLUSH_WAL | \ + PGSTAT_BACKEND_FLUSH_LOCK | \ + PGSTAT_BACKEND_FLUSH_VFDCACHE) extern bool pgstat_flush_backend(bool nowait, uint32 flags); extern bool pgstat_backend_flush_cb(bool nowait); diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index d195291a27a..9c9df43bc2f 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -2425,6 +2425,9 @@ pg_stat_user_tables| SELECT relid, WHERE ((schemaname <> ALL (ARRAY['pg_catalog'::name, 'information_schema'::name])) AND (schemaname !~ '^pg_toast'::text)); pg_stat_vfdcache| SELECT pg_stat_get_vfd_hits() AS hits, pg_stat_get_vfd_misses() AS misses, + pg_stat_get_vfd_cache_open_entries() AS open_entries, + pg_stat_get_vfd_cache_allocated_entries() AS allocated_entries, + pg_stat_get_vfd_cache_bytes() AS cache_bytes, pg_stat_get_vfd_max_open_fds() AS max_open_fds, CASE WHEN ((pg_stat_get_vfd_hits() + pg_stat_get_vfd_misses()) = 0) THEN NULL::double precision -- 2.34.1
