> -----Original Message-----
> From: pgsql-performance-owner@postgresql.org [mailto:pgsql-performance-
> owner@postgresql.org] On Behalf Of Thomas Kellerer
> Sent: Monday, May 06, 2013 1:12 PM
> To: pgsql-performance@postgresql.org
> Subject: Re: [PERFORM] Deterioration in performance when query executed
> in multi threads
>
> Anne Rosset, 06.05.2013 19:00:
> > Postgres version: 9.0.13
> >
> >> Work_mem is set to 64MB
> >> Shared_buffer to 240MB
> >> Segment_size is 1GB
> >> Wal_buffer is 10MB
> >
> > Artifact table: 251831 rows
> > Field_value table: 77378 rows
> > Mntr_subscription: 929071 rows
> > Relationship: 270478 row
> > Folder: 280356 rows
> > Item: 716465 rows
> > Sfuser: 5733 rows
> > Project: 1817 rows
> >
> > 8CPUs
> > RAM: 8GB
> >
>
> With 8GB RAM you should be able to increase shared_buffer to 1GB or
> maybe even higher especially if this is a dedicated server.
> 240MB is pretty conservative for a server with that amount of RAM
> (unless you have many other applications running on that box)
>
> Also what are the values for
>
> cpu_tuple_cost
> seq_page_cost
> random_page_cost
> effective_cache_size
>
> What kind of harddisk is in the server? SSD? Regular ones (spinning
> disks)?
>
>
>
Also, with 8 CPUs, your max connection_pool size shouldn't much bigger than 20.
Igor Neyman
