From 7f5a774d4262e10be077bed8cb6d5808ceb7a7d2 Mon Sep 17 00:00:00 2001 From: Daniil Davidov Date: Thu, 2 Apr 2026 04:20:35 +0700 Subject: [PATCH] v35--v36-diff --- doc/src/sgml/maintenance.sgml | 25 +++++++++++++------------ src/backend/access/common/reloptions.c | 3 ++- src/backend/commands/vacuumparallel.c | 2 +- src/backend/utils/misc/guc.c | 5 +++-- 4 files changed, 19 insertions(+), 16 deletions(-) diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml index eb6a07e086d..884ac898065 100644 --- a/doc/src/sgml/maintenance.sgml +++ b/doc/src/sgml/maintenance.sgml @@ -1179,23 +1179,24 @@ analyze threshold = analyze base threshold + analyze scale factor * number of tu phases in parallel using background workers (for the details of each vacuum phase, please refer to ). The degree of parallelism is determined by the number of indexes on the - relation that support parallel vacuum, limited by the PARALLEL - (for manual VACUUM) or the - parameters (for - autovacuum). + relation that support parallel vacuum. For manual VACUUM + it is limited by the PARALLEL option if any which is + further limited by . + For autovacuum it is limited by the + reloption if specified which is further limited by + parameter. Please + note that it is not guaranteed that the number of parallel workers that was + calculated will be used during execution. It is possible for a vacuum to + run with fewer workers than specified, or even with no workers at all. An index can participate in parallel vacuum if and only if the size of the index is more than . - Please note that it is not guaranteed that the number of parallel workers - specified in integer will be - used during execution. It is possible for a vacuum to run with fewer - workers than specified, or even with no workers at all. Only one worker - can be used per index. So parallel workers are launched only when there - are at least 2 indexes in the table. Workers for - vacuum are launched before the start of each phase and exit at the end of - the phase. These behaviors might change in a future release. + Only one worker can be used per index. So parallel workers are launched + only when there are at least 2 indexes in the table. + Workers for vacuum are launched before the start of each phase and exit at + the end of the phase. These behaviors might change in a future release. diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c index 3e832c3797e..d675d52531c 100644 --- a/src/backend/access/common/reloptions.c +++ b/src/backend/access/common/reloptions.c @@ -28,6 +28,7 @@ #include "commands/defrem.h" #include "commands/tablespace.h" #include "nodes/makefuncs.h" +#include "postmaster/bgworker_internals.h" #include "storage/lock.h" #include "utils/array.h" #include "utils/attoptcache.h" @@ -243,7 +244,7 @@ static relopt_int intRelOpts[] = RELOPT_KIND_HEAP, ShareUpdateExclusiveLock }, - -1, -1, 1024 + -1, -1, MAX_PARALLEL_WORKER_LIMIT }, { { diff --git a/src/backend/commands/vacuumparallel.c b/src/backend/commands/vacuumparallel.c index 683a0f34e24..bac3bd28214 100644 --- a/src/backend/commands/vacuumparallel.c +++ b/src/backend/commands/vacuumparallel.c @@ -70,7 +70,7 @@ typedef struct PVSharedCostParams /* * The generation counter is incremented by the leader process each time * it updates the shared cost-based vacuum delay parameters. Parallel - * vacuum workers compares it with their local generation, + * vacuum workers compare it with their local generation, * shared_params_generation_local, to detect whether they need to refresh * their local parameters. The generation starts from 1 so that a freshly * started worker (whose local copy is 0) will always load the initial diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 15048aa9e56..c4c3fbc4fe3 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -3359,10 +3359,11 @@ set_config_with_handle(const char *name, config_handle *handle, * Also allow normal setting if the GUC is marked GUC_ALLOW_IN_PARALLEL. * * Other changes might need to affect other workers, so forbid them. Note, - * that parallel autovacuum leader is an exception because only cost-based + * that parallel autovacuum leader is an exception because cost-based * delays need to be affected to parallel autovacuum workers. These * parameters are propagated to its workers during parallel vacuum (see - * vacuumparallel.c for details). + * vacuumparallel.c for details). All other changes will affect only the + * parallel autovacuum leader. */ if (IsInParallelMode() && !AmAutoVacuumWorkerProcess() && changeVal && action != GUC_ACTION_SAVE && -- 2.43.0