On Sat, 2022-05-07 at 12:06 +0200, Guillaume Lelarge wrote: > Le sam. 7 mai 2022 à 10:21, Ron <ronljohnsonjr@xxxxxxxxx> a écrit : > > On 5/6/22 21:35, Hasan Marzooq wrote: > > > I've some questions around Backup & Restore. > > > > > > 1: Is it necessary to perform a VACUUM and REINDEXING operation after restoring the > > > dump from Postgres 9.6 to Postgres 13? The dump size could be 1/2 TB to 1 TB. > > > > Perform VACUUM after there have been many updates and deletes. There have been zero > > updates and deleted after pg_restore; therefore, no need to vacuum. > > I disagree. You're right about the "zero updates and deletes", so no need to vacuum for bloat. > But you need vacuum to get the visibility map of each relation, so that the planner can use index-only scans. But from PostgreSQL v13 on, autovacuum is also triggered by INSERTs. So I'd say that there is nothing to do after restoring a pg_dump, except to wait until autovacuum is done. Yours, Laurenz Albe
