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Re: Long (really long) queries and not sure how to diagnose

From: Tony Day <tonyd(at)panztel(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-novice(at)postgresql(dot)org
Subject: Re: Long (really long) queries and not sure how to diagnose
Date: 2010-04-30 05:24:38
Message-ID: l2t22eb2d871004292224hef0a1dfas6068c40c57284d6a@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-novice
Hi Tom


Best guess from here is that some transaction took a write-preventing
> lock on that table, and then sat on it for a really long time.  If this
> were still going on, a look into pg_stat_activity and/or pg_locks would
> quickly prove or refute that theory.  Since it's not, there's probably
> not much you can do right now unless you have complete query logs to
> study.  What I'd suggest is familiarizing yourself with those views
> so you'll be better prepared to investigate next time.
>
>
Thanks for the response.

I have looked at pg_stat_activity previously but I had never heard of
pg_locks before.
Having said that, looking and knowing what to look for are quite different
:-)
I will spend some time trying to get to know both.

I am not sure what you mean by "complete query logs" but I do have a 1.3G
Postgresql log file from the day in question.
Is there a particular way that a "write-preventing lock" will be logged that
I can search for in that file?

Regards, Tony

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Next:From: Tom LaneDate: 2010-04-30 05:32:12
Subject: Re: Long (really long) queries and not sure how to diagnose
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