tohny at netcourrier.com writes:
> Thanks for your response Andrew for information, the master and the
> slave are on a server with the same configuration, and the same
> applications on it. So i wonder why my queries are slower on the
> slave than on the master. The only difference between the database
> is that the master is read/write and the slave read only.  Perhaps
> the slon process could have an impact on the performance ?? Have you
> another idea ?

Are you using the same VACUUM/ANALYZE regimen on both servers?

If that differs, and the subscriber node has obsolete pg_statistic
data, that would explain queries being way slower on the slave.

Aside from that, the fact that there are "read only" triggers on the
subscriber will have NO IMPACT on the speed of queries.  

Let me reiterate that: The _cluster_denyaccess_whatever trigger can
have NO IMPACT on the speed of queries.  It does not affect SELECT
queries in any way whatsoever.

Have you checked to see if the query plans differ on the provider and
subscriber nodes?  If they differ, due to statistics differing, that
would be the prime reason to expect different performance.  And that
would imply that you should run ANALYZE on the subscriber node's
tables.
-- 
"cbbrowne","@","ca.afilias.info"
<http://dev6.int.libertyrms.com/>
Christopher Browne
(416) 673-4124 (land)