Re: Patch pg_is_in_backup()

On Fri, Feb 3, 2012 at 10:47, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> On Fri, Feb 3, 2012 at 6:10 PM, Bernd Helmle <mailings(at)oopsware(dot)de> wrote:
>>
>>
>> --On 3. Februar 2012 13:21:11 +0900 Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
>> wrote:
>>
>>> It seems to be more user-friendly to introduce a view like pg_stat_backup
>>> rather than the function returning an array.
>>
>>
>> I like this idea. A use case i saw for monitoring backup_label's in the
>> past, was mainly to discover a forgotten exclusive pg_stop_backup() (e.g.
>> due to broken backup scripts). If the view would be able to distinguish
>> both, exclusive and non-exclusive backups, this would be great.
>
> Agreed. Monitoring an exclusive backup is very helpful. But I wonder
> why we want to monitor non-exclusive backup. Is there any use case?

Actually, we can already monitor much of the non-exclusive one through
pg_stat_replication. Including the info on when it was started (at
least in almost every case, that will be more or less the
backend_start time for that one)

> If we want to monitor non-exclusive backup, why not pg_dump backup?

.. which we can also monitor though pg_stat_activity by looking at
application_name (which can be faked of course, but still)

> If there is no use case, it seems sufficient to implement the function
> which reports the information only about exclusive backup.

Yeah, thinking more of it, i think I agree. But the function should
then probably be named in such a way that it's clear that we're
talking about exclusive backups, e.g. not pg_is_in_backup() but
instead pg_is_in_exclusive_backup() (renamed if we change it to return
the timestamp instead, of course, but you get the idea)

--
 Magnus Hagander
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