Re: pg9.6: no backup history file (*.backup) created on hot standby

On Tue, 2018-10-09 at 16:55 +0900, Michael Paquier wrote:
> On Tue, Oct 09, 2018 at 03:26:35PM +0800, magodo wrote:
> > Yes, but does this differ whether I'm archiving a general WAL or
> > archiving the backup history? I mean if user doesn't handle
> > duplicate
> > archive, then pg_wal will still be filled up when archiving WAL.
>
> A WAL segment has a unique name, and would be finished to be used
> once.
> The problem with backup history files on standbys is that the *same*
> file can could finish by being generated *multiple* times with base
> backups taken in parallel. That's a completely different story, and
> the
> window to those backup history files having the same name gets larger
> the more the window between two checkpoints is. That's a problem I
> studied a couple of months back.
> --
> Michael

I just realized that doing basebackup on standby have other different
behaviors than it on primary, for example, it will not switch wal on
begin or end.

So do you just mean if there is no wal switch on primary(suppose
currently on 0000000100000002), then each basebackup made on standby
will always generate a same named backup history(e.g.
0000000100000002.backup)?

---
Magodo