Re: pg_start_backup does not actually allow for consistent, file-level backup

On Mon, Jun 8, 2015 at 3:13 PM, otheus uibk <otheus(dot)uibk(at)gmail(dot)com> wrote:

> Thank you, all. The manual for 9.4 is indeed clearer on this point than
> the 9.1 version.
>

Just to nit-pick, I see nowhere in either version of the manual the
indication that it is normal for postgresql to continue to update files in
its data catalog between pg_start_backup and pg_stop_backup. The closest I
see comes in this paragraph:

** Some file system backup tools emit warnings or errors if the files they
are trying to copy change while the copy proceeds. When taking a base
backup of an active database, this situation is normal and not an error.

Does "this situation" refer to the tools emitting warnings or to the fact
that postgresql is updating the files? It might be the case, for instance,
that timestamps are updated but not the contents of the files (this is what
I had assumed prior to today).

--
Otheus
otheus(dot)uibk(at)gmail(dot)com
otheus(dot)shelling(at)uibk(dot)ac(dot)at