Re: Low Performance for big hospital server ..

On Tue, 4 Jan 2005 amrit@health2.moph.go.th wrote:

> Today is the first official day of this weeks and the system run better in
> serveral points but there are still some points that need to be corrected. Some
> queries or some tables are very slow. I think the queries inside the programe
> need to be rewrite.
> Now I put the sort mem to a little bit bigger:
> sort mem = 16384       increase  the sort mem makes no effect on the slow point
> eventhough there is little connnection.
> shared_buffers = 27853
> effective cache = 120000

Even though others have said otherwise, I've had good results from setting
sort_mem higher -- even if that is per query.

>
> I will put more ram but someone said RH 9.0 had poor recognition on the Ram
> above 4 Gb?

I think they were refering to 32 bit architectures, not distributions as
such.

> Should I close the hyperthreading ? Would it make any differnce between open and
> close the hyperthreading?
> Thanks for any comment

In my experience, the largest performance increases come from intensive
analysis and optimisation of queries. Look at the output of EXPLAIN
ANALYZE for the queries your application is generating and see if they can
be tuned in anyway. More often than not, they can.

Feel free to ask for assistence on irc at irc.freenode.net #postgresql.
People there help optimise queries all day ;-).

> Amrit
> Thailand

Gavin