"Merlin Moncure" <mmoncure(at)gmail(dot)com> writes:
> can't thing of anything, I'm running completely stock, did you do a
> optimize table foo?
Nope, never heard of that before. But I did it, and it doesn't seem to
have changed my results at all.
> mysql> select user_id, acc_id, max(sample_date) from usage_samples group by 1,2
> 939 rows in set (0.07 sec)
0.07 seconds is not impossibly out of line with my result of 0.15 sec,
maybe your machine is just 2X faster than mine. This is a 2.8GHz dual
Xeon EM64T, what are you testing? You said "less than 20 msec" before,
what was that on?
regards, tom lane