On 5/25/06, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Tom Lane <tgl@sss.pgh.pa.us> writes:
> > "Merlin Moncure" <mmoncure@gmail.com> 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