Re: big database performance

Adrian Moisey wrote:
> Hi
>
> We recently converted to postgres (from mssql) and we're having
> performance issues.  Not all the issues are related to postgres, but
> we're trying to sort everything out.
>
> The server is running ubuntu Gutsy with the database stored on a IBM
> SAN.  It is a Dell box with dual quad core 2.00GHz Xeons and 8GB RAM.
>
>
> The database is about 71GB in size.
>
> I've looked at the postgres config files and we've tweaked as much as
> our knowledge allows.
>
> Can someone shed some light on the settings I should use ?

Umpf that isn't quite enough info :) but assuming you are running 8.2.x:

Start with 1GB shared_buffers (you may be able to go hire), 4MB
work_mem, wal_sync_method = open_sync, checkpoint_segments = 30,
default_statistics_target = 150, effective_cache_size = 6GB .


Restart, VACUUM ANALYZE VERBOSE, post back last 4 lines of output.

Other good items to know:

64bit Gutsy?
How is the SAN connected?
What does mpstat 5 (3 iterations) say?
Even better what does sar -A say over a 24 hour period?

Sincerely,

Joshua D. Drake




>
>
> Thanks in advance