Re: log_duration is redundant, no? - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: log_duration is redundant, no?
Date
Msg-id 200609072252.k87MqAu09347@momjian.us
Whole thread Raw
In response to Re: log_duration is redundant, no?  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: log_duration is redundant, no?  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> > If you are using an external tool, can't you just restrict what you
> > display based on the logged duration?
> 
> I think his basic complaint is that doing the full logging pushup for
> even short-duration queries is too expensive, and that logging only the
> duration and not the query text or parameters makes a significant speed
> difference.  I'm not at all sure that I buy that, but if it's true then
> subsequent filtering obviously doesn't help.

Well, except for bind, all the log output display is zero cost, just a
printf(), as I remember.  The only cost that is significant, I think, is
the timing of the query, and that is happening for all the setttings
discussed.

--  Bruce Momjian   bruce@momjian.us EnterpriseDB    http://www.enterprisedb.com
 + If your life is a hard drive, Christ can be your backup. +


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