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

[HECTOR INGERTO <hector_25e@xxxxxxxxxxx>]

> 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?