[pgpool-general: 2325] Re: thousands of queries to pg_class / second

Nathan Brennan nathan at healthengine.com.au
Wed Dec 4 15:37:31 JST 2013


ok thanks,

I have disabled the check_temp_table as we don't use temp tables which
removes the pg_temp queries, however there is still alot of queries for
SELECT count(*) FROM pg_catalog.pg_class AS c WHERE c.relname = 'table' AND
c.relpersistence = 'u' to me this seems like a check to see if the table
exists, is there a way to cache this ?

*Nathan Brennan* *BCS*
Lead Developer

*T:* +61 8 9482 3981 | *E:* nathan at healthengine.com.au

<http://healthengine.com.au/>      <https://twitter.com/healthengine>
<https://www.facebook.com/HealthEngine>



On Wed, Dec 4, 2013 at 12:51 PM, Tatsuo Ishii <ishii at postgresql.org> wrote:

> > Hi,
> >
> > Is there a way to cache these queries or turn them off as pgpool is doing
> > thousands of them a second.I tried setting relcache_expire=60 but it
> > doesn't seem to help.
> >
> > example queries:
> >
> > SELECT count(*) FROM pg_class AS c, pg_namespace AS n WHERE c.relname =
> > 'table' AND c.relnamespace = n.oid AND n.nspname = 'pg_catalog'
> >  SELECT count(*) FROM pg_class AS c, pg_namespace AS n WHERE c.relname =
> > 'table' AND c.relnamespace = n.oid AND n.nspname ~ '^pg_temp_'
>
> You can avoid temp table related queries by turning check_temp_table
> to off (of course you need to be sure that you are not using temp
> tables).
>
> Also relcache_expire = 0 will be more effective if you want to reduce
> the number of queries.
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> English: http://www.sraoss.co.jp/index_en.php
> Japanese: http://www.sraoss.co.jp
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.sraoss.jp/pipermail/pgpool-general/attachments/20131204/f579c06c/attachment.html>


More information about the pgpool-general mailing list