On 5/25/06, Tom Lane <tgl@xxxxxxxxxxxxx> wrote:
Tom Lane <tgl@xxxxxxxxxxxxx> writes: > "Merlin Moncure" <mmoncure@xxxxxxxxx> writes: >> recent versions of mysql do much better, returning same set in < 20ms.
Are you sure you measured that right? I tried to duplicate this using mysql 5.0.21, and I see runtimes of 0.45 sec without an index and 0.15 sec with. This compares to psql times around 0.175 sec. Doesn't look to me like we're hurting all that badly, even without using the index.
Well, my numbers were approximate, but I tested on a few different machines. the times got closer as the cpu speed got faster. pg really loves a quick cpu. on 600 mhz p3 I got 70ms on mysql and 1050ms on pg. Mysql query cache is always off for my performance testing. My a and b columns were ID columns from another table, so I rewrote the join and now pg is smoking mysql (again). To quickly answer the other questions: 1. no, not testing innodb 2, rows are narrow Merlin
