Re: [PERFORM] Optimization postgresql 8.1.4 FC 6 X64 ?
amrit angsusingh wrote: I try to change my database server from the older one ie. 2Cpu Xeon 2.4 32 bit 4Gb SDram Hdd SCSI RAID 5 and FC 3 ix86 with 7..4.7 PG to the newer one with 2CPU Xeon 3.0 64 Bit 4Gb DDRram SCSI Raid5 and FC6 X64 PG 8.14 and try to use rather the same parameter from the previous postgresql.conf :- ... I use pgbench to test the speed of my older database server and the result is bash-3.00$ pgbench test -t 20 -c 30 -s 50 ... -t 20 is not enough to give repeatable results. Try something like -t 1000. The speed of pgbench in that configuration (scaling factor 50, fsync enabled) is limited by the speed you can fsync the WAL. There isn't much you can do in postgresql.conf for that. If you get similar results with higher -t setting, it may be because your new RAID and drives have slightly higher latency. You're better off testing with real queries with your real database. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com ---(end of broadcast)--- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
Re: [PERFORM] [HACKERS] EXISTS optimization
On Fri, Mar 23, 2007 at 05:30:27PM -0500, Kevin Grittner wrote: > I don't understand -- TRUE OR UNKNOWN evaluates to TRUE, so why would > the IN need to continue? I'm not quite following the rest; could you > elaborate or give an example? (Sorry if I'm lagging behind the rest > of the class here.) You're right, I'm getting confused with the interaction of NULL and NOT IN. The multiple evaluation thing still applies, but that's minor. Have a nice day, -- Martijn van Oosterhout http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to > litigate. signature.asc Description: Digital signature
Re: [PERFORM] Optimization postgresql 8.1.4 FC 6 X64 ?
I also think there have been changes in pgbench itself. Make sure you run the same pgbench on both servers. Dave On 24-Mar-07, at 6:44 AM, Heikki Linnakangas wrote: amrit angsusingh wrote: I try to change my database server from the older one ie. 2Cpu Xeon 2.4 32 bit 4Gb SDram Hdd SCSI RAID 5 and FC 3 ix86 with 7..4.7 PG to the newer one with 2CPU Xeon 3.0 64 Bit 4Gb DDRram SCSI Raid5 and FC6 X64 PG 8.14 and try to use rather the same parameter from the previous postgresql.conf :- ... I use pgbench to test the speed of my older database server and the result is bash-3.00$ pgbench test -t 20 -c 30 -s 50 ... -t 20 is not enough to give repeatable results. Try something like - t 1000. The speed of pgbench in that configuration (scaling factor 50, fsync enabled) is limited by the speed you can fsync the WAL. There isn't much you can do in postgresql.conf for that. If you get similar results with higher -t setting, it may be because your new RAID and drives have slightly higher latency. You're better off testing with real queries with your real database. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com ---(end of broadcast)--- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate ---(end of broadcast)--- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
Re: OT: Munin (was Re: [PERFORM] Determining server load from client)
On 3/21/07, Erik Jones <[EMAIL PROTECTED]> wrote: On Mar 21, 2007, at 4:13 PM, Tobias Brox wrote: [Erik Jones - Wed at 09:31:48AM -0500] I use cacti (http://cacti.net) which does the same thing that munin does but in php instead. Here's what I use to db stats to it (again, php): I haven't tried cacti, but our sysadm has done a little bit of research and concluded "cacti is better". Maybe some day we'll move over. Munin is generating all the graphs statically every fifth minute, while cacti generates them on demand as far as I've understood. The munin approach is pretty bloat, since one usually would watch the graphs much more seldom than what they are generated (at least, we do). That's not really an argument since CPU is cheap nowadays - but a real argument is that the munin approach is less flexible. One would like to adjust the graph (like, min/max values for both axis) while watching quite some times. Well, by "default", Cacti polls all of the data sources you've set up every five minutes as well as that's how the docs instruct you to set up the cron job for the poller. However, with a little understanding of how the rrdtool rras work, you could definitely poll more often and simply edit the existing rras and datasources to expect that or create new ones. And, yes, the graph customization is pretty cool although for the most part the just map what's available from the rrdtool graph functionality. If you do decide to set up Cacti I suggest you go straight to the faq section of the manual and read the part about going from a simple script to a graph. The main manual is almost entirely centered on the built-in networking (e.g. snmp) data sources and, as such, doesn't do much for explaining how to set up other data sources. Has anyone had experience setting up something similar with Nagios? We monitor servers using nagios and not having to install additional software (cacti/munin) for postgres resource usage monitoring would be great. Thanks in advance!
