That fsync off would make me very unhappy in a production environment .... not that turning it on would help postgres, but ... one advantage of postgres is its reliability under a "pull the plug" scenario, but this setting defeats that. FWIW, Xeon has gotten quite negative reviews in these quarters (Opteron seems to do way better), IIRC, and I know we've had issues with Dell's disk i/o, admittedly on a different box. Quite interesting results, even if a bit disappointing to a (newly minted) fan of postgres. I'll be quite interested to hear more. Thanks for the work, although it seems like some of it won;t be able to released, unless Oracle has given some new blessing to releasing benchmark results. Greg Williamson DBA GlobeXplorer LLC -----Original Message----- From: pgsql-performance-owner@xxxxxxxxxxxxxx on behalf of Olivier Andreotti Sent: Thu 5/18/2006 2:57 AM To: pgsql-performance@xxxxxxxxxxxxxx Cc: Subject: [PERFORM] Benchmarck PostgreSQL 8.1.4 MySQL 5.0.20 and Oracle 10g2 Hello, I'm running a benchmark with theses 3 databases, and the first results are not very good for PostgreSQL. PostgreSQL is 20% less performance than MySQL (InnoDB tables) My benchmark uses the same server for theses 3 databases : Dell Power edge - Xeon 2.8 Ghz - 2 Go Ram - 3 SCSI disks - Debian Sarge - Linux 2.6 The transactions are a random mix of request in read (select) and write (insert, delete, update) on many tables about 100 000 to 15 000 000 rows. Transactions are executed from 500 connections. For the tunning of PostgreSQL i use official documentation and theses web sites : http://www.revsys.com/writings/postgresql-performance.html http://www.varlena.com/GeneralBits/Tidbits/annotated_conf_e.html Some important points of my postgresql.conf file : max_connections = 510 shared_buffer = 16384 max_prepared_transactions = 510 work_mem = 1024 maintenance_work_mem = 1024 fsync = off wal_buffers = 32 commit_delay = 500 checkpoint_segments = 10 checkpoint_timeout = 300 checkpoint_warning = 0 effective_cache_size = 165 000 autovaccuum = on default_transaction_isolation = 'read_committed' What do you think of my tunning ? Best regards. O.A ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings !DSPAM:446c453a198591465223968!
