TIL: Postgres Replication Slots

Replica liest WAL-Segmente. Primary räumt WAL-Segmente auf:

the server might recycle old WAL segments before the standby has received them [1]

Früher hat man gewartet und gehofft [2].

Mit Replication Slots merkt sich Primary, welchen Stand Replica hat, und weiß daher, welche WAL-Segmente entfernt werden dürfen.

Befehle

Replication Slot anlegen

SELECT pg_create_physical_replication_slot('my-slot');

Fehler beim pg_basebackup? Replication Slot killen:

SELECT pg_drop_replication_slot('my-slot');

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[1]

https://www.postgresql.org/docs/current/warm-standby.html#STREAMING-REPLICATION)”.

[2]

setting wal_keep_size to a value large enough to ensure that WAL segments are not recycled too early

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