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| author | Andres Freund <andres@anarazel.de> | 2023-04-08 02:20:01 -0700 |
|---|---|---|
| committer | Andres Freund <andres@anarazel.de> | 2023-04-08 02:20:05 -0700 |
| commit | 0fdab27ad68a059a1663fa5ce48d76333f1bd74c (patch) | |
| tree | 3d29650901130428712f71cbb8b57cb19f738f1a /src/include | |
| parent | e101dfac3a53c20bfbf1ca85d30a368c2954facf (diff) | |
| download | postgresql-0fdab27ad68a059a1663fa5ce48d76333f1bd74c.tar.gz | |
Allow logical decoding on standbys
Unsurprisingly, this requires wal_level = logical to be set on the primary and
standby. The infrastructure added in 26669757b6a ensures that slots are
invalidated if the primary's wal_level is lowered.
Creating a slot on a standby waits for a xl_running_xact record to be
processed. If the primary is idle (and thus not emitting xl_running_xact
records), that can take a while. To make that faster, this commit also
introduces the pg_log_standby_snapshot() function. By executing it on the
primary, completion of slot creation on the standby can be accelerated.
Note that logical decoding on a standby does not itself enforce that required
catalog rows are not removed. The user has to use physical replication slots +
hot_standby_feedback or other measures to prevent that. If catalog rows
required for a slot are removed, the slot is invalidated.
See 6af1793954e for an overall design of logical decoding on a standby.
Bumps catversion, for the addition of the pg_log_standby_snapshot() function.
Author: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>
Author: Andres Freund <andres@anarazel.de> (in an older version)
Author: Amit Khandekar <amitdkhan.pg@gmail.com> (in an older version)
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: FabrÌzio de Royes Mello <fabriziomello@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-By: Robert Haas <robertmhaas@gmail.com>
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/access/xlog.h | 1 | ||||
| -rw-r--r-- | src/include/catalog/catversion.h | 2 | ||||
| -rw-r--r-- | src/include/catalog/pg_proc.dat | 3 |
3 files changed, 5 insertions, 1 deletions
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index cfe5409738..48ca852381 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -230,6 +230,7 @@ extern void XLOGShmemInit(void); extern void BootStrapXLOG(void); extern void InitializeWalConsistencyChecking(void); extern void LocalProcessControlFile(bool reset); +extern WalLevel GetActiveWalLevelOnStandby(void); extern void StartupXLOG(void); extern void ShutdownXLOG(int code, Datum arg); extern void CreateCheckPoint(int flags); diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h index 33a77fe6ae..54f3ddcd97 100644 --- a/src/include/catalog/catversion.h +++ b/src/include/catalog/catversion.h @@ -57,6 +57,6 @@ */ /* yyyymmddN */ -#define CATALOG_VERSION_NO 202304074 +#define CATALOG_VERSION_NO 202304075 #endif diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 067bee8198..b516cee8bd 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6432,6 +6432,9 @@ { oid => '2848', descr => 'switch to new wal file', proname => 'pg_switch_wal', provolatile => 'v', prorettype => 'pg_lsn', proargtypes => '', prosrc => 'pg_switch_wal' }, +{ oid => '9658', descr => 'log details of the current snapshot to WAL', + proname => 'pg_log_standby_snapshot', provolatile => 'v', prorettype => 'pg_lsn', + proargtypes => '', prosrc => 'pg_log_standby_snapshot' }, { oid => '3098', descr => 'create a named restore point', proname => 'pg_create_restore_point', provolatile => 'v', prorettype => 'pg_lsn', proargtypes => 'text', |