brauagustin-susc@xxxxxxxxxxxx wrote: > Recently I have installed a brand new server with a Pentium IV 3.2 GHz, SATA Disk, 2GB of Ram in Debian 4.0r1 with PostgreSQL 8.2.4 (previously a 8.1.9). > I have other similar server with an IDE disk, Red Hat EL 4 and PostgreSQL 8.2.3 > > I have almost the same postgresql.conf in both servers, but in the new one (I have more work_mem than the other one) things go really slow. I began to monitor i/o disk and it's really ok, I have test disk with hdparm and it's 5 times faster than the IDE one. > Running the same queries in both servers in the new one it envolves almost 4 minutes instead of 18 seconds in the old one. > Both databases are the same, I have vacuum them and I don't know how to manage this issue. Have you ANALYZEd all tables? Try running EXPLAIN ANALYZE on the query on both servers, and see if they're using the same plan. > The only weird thing is than in the older server running the query it uses 30% of CPU instead of 3 o 5 % of the new one!!! That implies that it's doing much more I/O on the new server, so the CPU just sits and waits for data to arrive from the disk. That does iostat say about disk utilization on both servers? -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@xxxxxxxxxxxxxx so that your message can get through to the mailing list cleanly
