> Using the exact same data, and the exact same queries (dbi is cool):
> MySQL: 0.498u 0.150s 0:02.50 25.6% 10+1652k 0+0io 0pf+0w
> PgSQL: 0.494u 0.061s 0:19.78 2.7% 10+1532k 0+0io 0pf+0w
> >From the 'time' numbers, MySQL is running ~17sec faster, but uses up 23%
> more CPU to do this...so where is our slowdown?
I don't remember if you gave details on the sizes of tables, but in
any case I'm going to guess that you are spending almost all of your
time in the optimizer. Try manipulating the parameters to force the
genetic optimizer and see if it helps. Lots of quals but only two
tables gives you a non-optimal case for the default exhaustive
optimizer.
- Thomas
--
Thomas Lockhart lockhart(at)alumni(dot)caltech(dot)edu
South Pasadena, California