Hi Thomas, It is not a dedicated box (we have Jboss running too). cpu_tuple_cost | 0.01 seq_page_cost | 1 random_page_cost | 4 effective_cache_size | 512MB We have the data directory on nfs (rw,intr,hard,tcp,rsize=32768,wsize=32768,nfsvers=3,tcp). Note that we have also tested putting the data directory on local disk and didn't find a big improvement. Thanks, Anne -----Original Message----- From: pgsql-performance-owner@xxxxxxxxxxxxxx [mailto:pgsql-performance-owner@xxxxxxxxxxxxxx] On Behalf Of Thomas Kellerer Sent: Monday, May 06, 2013 10:12 AM To: pgsql-performance@xxxxxxxxxxxxxx Subject: Re: 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)? -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
