work_mem = 131072 # min 64, size in KB shared_buffers = 16000 # min 16, at least max_connections*2, 8KB each checkpoint_segments = 128 # in logfile segments, min 1, 16MB each effective_cache_size = 750000 # typically 8KB each fsync=false # turns forced synchronization on or off ------------------------------------------ On Bizgres (0_7_2) running on a 2GHz Opteron: ------------------------------------------ [EMAIL PROTECTED] bayesBenchmark]$ ./test.sh
real 0m38.348s user 0m1.422s sys 0m1.870s ------------------------------------------ On a 2.4GHz AMD64: ------------------------------------------ [EMAIL PROTECTED] bayesBenchmark]$ ./test.sh real 0m35.497s user 0m2.250s sys 0m0.470s Now we turn fsync=true: ------------------------------------------ On a 2.4GHz AMD64: ------------------------------------------ [EMAIL PROTECTED] bayesBenchmark]$ ./test.sh real 2m7.368s user 0m2.560s sys 0m0.750s I guess we see the real culprit here. Anyone surprised it's the WAL? - Luke ________________________________ From: [EMAIL PROTECTED] on behalf of Andrew McMillan Sent: Thu 7/28/2005 10:50 PM To: Matthew Schumacher Cc: pgsql-performance@postgresql.org Subject: Re: [PERFORM] Performance problems testing with Spamassassin 3.1.0 On Thu, 2005-07-28 at 16:13 -0800, Matthew Schumacher wrote: > > Ok, I finally got some test data together so that others can test > without installing SA. > > The schema and test dataset is over at > http://www.aptalaska.net/~matt.s/bayes/bayesBenchmark.tar.gz > > I have a pretty fast machine with a tuned postgres and it takes it about > 2 minutes 30 seconds to load the test data. Since the test data is the > bayes information on 616 spam messages than comes out to be about 250ms > per message. While that is doable, it does add quite a bit of overhead > to the email system. On my laptop this takes: real 1m33.758s user 0m4.285s sys 0m1.181s One interesting effect is the data in bayes_vars has a huge number of updates and needs vacuum _frequently_. After the run a vacuum full compacts it down from 461 pages to 1 page. Regards, Andrew. ------------------------------------------------------------------------- Andrew @ Catalyst .Net .NZ Ltd, PO Box 11-053, Manners St, Wellington WEB: http://catalyst.net.nz/ PHYS: Level 2, 150-154 Willis St DDI: +64(4)803-2201 MOB: +64(272)DEBIAN OFFICE: +64(4)499-2267 I don't do it for the money. -- Donald Trump, Art of the Deal ------------------------------------------------------------------------- ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
