Re: Backup Question

> Wrong. The database cannot check all data for consistency
> upon backup. For one, that would take way too long.

Well, what I meant, was that it would stop the database if it couldn't
apply one of the transaction logs for whatever reason. It wasn't
"inconsistent enough" for that. :)

> If you backup the standby, then you won't have a backup_label file.
> You cannot restore a backup without that.

Well, the backup_label gets copied to the archive log path when
pg_stop_backup gets called. So, I do have it. But beyond that, I have
the start/stop WAL locations, so I can get all the required files to apply,
which are all that is really necessary.

> Moreover, recovery needs a checkpoint/restartpoint to start.
> Restartpoints on the standby won't be the same as checkpoints
> on the primary, so I believe that even with the backup_label
> file you would not be able to restore the data.

I suppose I could build in a function to pause the backup until the
restartpoint replays on the replica. Then at least, the backup "starts"
on both systems with the same assumptions.

--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd | Suite 500 | Chicago IL, 60604
312-676-8870
sthomas(at)optionshouse(dot)com

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