From: Cosimo Streppone <cosimo@streppone.it>
To: Mindaugas Riauba <mind@bi.lt>
Cc: pgsql-performance@postgresql.org
Subject: Re: PostgreSQL strugling during high load
Date: Fri, 13 May 2005 17:23:13 +0200
Message-ID: <4284C661.4050406@streppone.it> (raw)
In-Reply-To: <022901c557c5$73df1220$f20214ac@bite.lt>
References: <01cc01c557ba$a4fdb0b0$f20214ac@bite.lt>
<23217.1115991763@sss.pgh.pa.us>
<022901c557c5$73df1220$f20214ac@bite.lt>
Mindaugas Riauba wrote:
>>The "vacuum cost" parameters can be adjusted to make vacuums fired
>>by pg_autovacuum less of a burden. I haven't got any specific numbers
>>to suggest, but perhaps someone else does.
>
> It looks like that not only vacuum causes our problems. vacuum_cost
> seems to lower vacuum impact but we are still noticing slow queries "storm".
> We are logging queries that takes >2000ms to process.
> And there is quiet periods and then suddenly 30+ slow queries appears in
> log within the same second. What else could cause such behaviour?
I've seen that happen when you're placing (explicitly or
*implicitly*) locks on the records you're trying to update/delete.
If you're willing to investigate, `pg_locks' system view holds
information about db locks.
--
Cosimo
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To: pgsql-performance@postgresql.org
Cc: cosimo@streppone.it, mind@bi.lt
Subject: Re: PostgreSQL strugling during high load
In-Reply-To: <4284C661.4050406@streppone.it>
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