On 5/26/06, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> > 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?
600 mhz p3: 70 ms, 1100 ms slow case
1600 mhz p4: 10-30ms (mysql timer not very precise) 710ms slow case
quad opteron 865: 0 :-)
dual p3 1133 Mhz xeon, mysql 4.0.16: 500 ms
using steinar's 'substitute group by' for pg I get 40ms on the p3 and
low times on all else. your time of 150 ms is looking like the slow
case on my results.
merlin
