> > 1. create table test (id int4, aaa int4, primary key (id)); > > 2. insert into test values (0,1); > > 3. Execute "update test set aaa=1 where id=0;" in an endless loop > > > > I just did the test on PostgreSQL 7.4.12 and MySQL 5.0.22 (MyISAM, > > sorry had no configured InnoDB). Ubuntu 6.0.6, AMD64, 2GB, default > > database settings. > > > > MySQL performs very well, approximately 15000-20000 updates per second > > with no degradation of performance. > > > > PostgreSQL does approximately 1600 records per second for the first > > 10000, then 200rps for the first 100k records, and then slower and > > slower downgrading to 10-20 rps(!!!) when reaching 300k. > > Something is wrong with your test code. If I had to guess I would say > you did all the updates in a single transaction without committing > them, in which case yes it will slow down until you commit. No, I'm not doing all the updates in a single transaction. Is it so hard to repeat my test in your environment? :) It would take 5min to see my point.
