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RE: Are ZFS snapshots unsafe when PGSQL is spreading through multiple zpools?

HECTOR INGERTO <hector_25e@hotmail.com>

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From: HECTOR INGERTO <hector_25e@hotmail.com>
To: Laurenz Albe <laurenz.albe@cybertec.at>, Magnus Hagander <magnus@hagander.net>
Cc: "pgsql-general@postgresql.org <pgsql-general@postgresql.org>" <pgsql-general@postgresql.org>
Date: 2023-01-17T15:22:02Z
Lists: pgsql-general 
> Another case: a transaction COMMITs, and a slightly later transaction reads the data
> and sets a hint bit.  If the snapshot of the file system with the data directory in it
> is slightly later than the snapshot of the file system with "pg_wal", the COMMIT might
> not be part of the snapshot, but the hint bit could be.
>
> Then these uncommitted data could be visible if you recover from the snapshot.
>
> Yours,
> Laurenz Albe

Thank you all. I have it clearer now.

As a last point. Making the snapshot to the WAL dataset first or last would make any difference?