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Subject: Re: Return pg_control from pg_backup_stop().
To: Haibo Yan <tristan.yim@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>,
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From: David Steele <david@pgbackrest.org>
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Date: Tue, 17 Mar 2026 07:05:06 +0000 (UTC)
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On 3/17/26 12:16, Haibo Yan wrote:

> I have not read the code yet, so this may already be answered there, but 
> I had a question about the proposal itself. This patch protects against 
> a missing backup_label, but what about a wrong one? If a user restores a 
> backup_label file from a different backup, the existence check alone 
> would not detect that. Do we need some consistency check between the 
> returned pg_control copy and the backup_label contents, or is the 
> intended scope here limited to the “missing file” case only?

Thank you for having a look!

The goal here is only to check for a missing backup_label. The general 
problem is that PostgreSQL suggests that removing backup_label might be 
a good idea so the user does it:

If you are not restoring from a backup, try removing the file 
\"%s/backup_label\"

The user *could* copy a backup_label from another backup and there are 
ways we could detect that but I feel that should be material for a 
separate patch.

Regards,
-David