Re: PATCH: regular logging of checkpoint progress

On 2 Září 2011, 9:47, Magnus Hagander wrote:
> On Thu, Sep 1, 2011 at 21:59, Tomas Vondra <tv(at)fuzzy(dot)cz> wrote:
>> I've prepared a significantly simplified version of the patch. The two
>> main changes are
>>
>> (a) it does not update the pg_stat_bgwriter anymore, it just prints an
>> info to the server log
>> (b) a new GUC is not required, it's driven by the log_checkpoints
>
> The comment still refers to the checkpoint_update_limit.

OK, I'll fix that.

>> This version will log at least 10 'checkpoint status' lines (at 10%,
>> 20%,
>> 30%, ...) and whenever 5 seconds since the last log elapses. The time is
>> not checked for each buffer but for 128 buffers.
>>
>> So if the checkpoint is very slow, you'll get a message every 5 seconds,
>> if it's fast you'll get 10 messages.
>
> I would personally find this very annoying. If I read it correctly,
> anybody with a database with no problem at all but that has
> log_checkpoints on suddenly got at least 10 times as many messages? I
> generally try to advise my clients to *not* log excessively because
> then they will end up not bothering to read the logs...

What about logging it with a lower level, e.g. NOTICE instead of the
current LOG? If that's not a solution then a new GUC is needed I guess.

Tomas