Re: PostgreSQL on Webmin

On Monday 16 March 2009 17:55:00 Kostadin Solakov wrote:
> John R Pierce wrote:
>
> thats odd, as a domain socket should be slightly -faster- than a tcp/ip
> socket. now, since you say 'previous host' I could wonder if other
> configuration items are impacting this, such as buffer sizes in
> postgresql.conf, relative speed of disk controllers, etc. or perhaps
> this new database hasn't been analyzed since it was populated, or its
> indexes need rebuilding, or something similar...
>
> I think that is the issue. Previous server was old machine and the
> settings in postgresql.conf were the default ones.
> The new machine is Xeon quad with 8GB ram and I already made some
> changes in postgresql.conf, but still no result.
> I followed the instructions on
> http://www.powerpostgresql.com/PerfList/ and made the following changes:
>
> shared_buffers = 50000
> work_mem = 512000
> checkpoint_segments = 32
> effective_cache_size = 200000
>
> Also I ran REINDEX on the DB and VACUUM VERBOSE ANALYZE on each
> table, but still the results are the same as before.
> What are the settings you recommend for this server?
> The application that is going to use it has a very demanding back
> end, it parses very large XML files (20+) and saves the data in the DB.
>

Unless you're actually running 8.2, that information is a bit out of date.
There's a better write up at
http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server

Once you go through that and restart, if it's still slow, can you paste
explain analyze from the two different servers?

--
Robert Treat
Conjecture: http://www.xzilla.net
Consulting: http://www.omniti.com