Re: Why so many xlogs?

2010/11/1 hubert depesz lubaczewski <depesz@depesz.com>:
> On Mon, Nov 01, 2010 at 07:18:22PM +0100, Filip Rembiałkowski wrote:
>> 2010/11/1 hubert depesz lubaczewski <depesz@depesz.com>:
>>
>> > as I understand, max number of xlog files in pg_xlog should be ( 1 + 2 *
>> > checkpoint_segments ).
>>
>> why?
>>
>> for a server overloaded with R/W transactions, it's possible to go beyond this.
>> checkpoints just do not keep up.
>> right now I have an 8.3 with checkpoint_segments=3, constantly running
>> pgbench and I see 8 WAL segments.
>
> you will notice in the logs that the system doesn't look like very
> loaded.
> i mean - there is fair amount of work, but nothing even resembling
> "overloaded".

There exists some checkpoint which occur more frequently than perhaps
expected. (less than 15 minutes)...

The logline about checkpoint might be usefull. Still I wonder what
your question is exactly ?

>
> Best regards,
>
> depesz
>
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Cédric Villemain               2ndQuadrant
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