Hi Ken, Thanks for your answer. My test is actually running with jboss 7/jdbc and the connection pool is defined with min-pool-size =10 and max-pool-size=400. Why would you think it is an issue with the connection pool? Thanks, Anne -----Original Message----- From: ktm@xxxxxxxx [mailto:ktm@xxxxxxxx] Sent: Wednesday, May 01, 2013 7:13 AM To: Anne Rosset Cc: pgsql-performance@xxxxxxxxxxxxxx Subject: Re: Deterioration in performance when query executed in multi threads On Wed, May 01, 2013 at 02:05:06PM +0000, Anne Rosset wrote: > Hi all, > We are running a stress test that executes one select query with multiple threads. > The query executes very fast (10ms). It returns 100 rows. I see deterioration in the performance when we have multiple threads executing the query. With 100 threads, the query takes between 3s and 8s. > > I suppose there is a way to tune our database. What are the parameters > I should look into? (shared_buffer?, wal_buffer?) > > Thanks for your help, > Anne Try a connection pooler like pgbouncer to keep the number of simultaneous queries bounded to a reasonable number. You will actually get better performance. Regards, Ken -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
