Brian Cox <brian.cox@ca.com> wrote:
> cemdb=# explain select min(ts_id) from
> ts_stats_transet_user_interval a
> where 0=0 and a.ts_interval_start_time >= '2009-6-16 01:00' and
> a.ts_interval_start_time < '2009-6-16 02:00';
> seems like max() shouldn't take any longer than min() and certainly
> not 10 times as long. Any ideas on how to determine the max more
> quickly?
Is there any correlation between ts_id and ts_interval_start_time?
Perhaps if you tried min and max with different time ranges it would
find a row on a backward scan faster. It'll take ten times as long if
it has to scan through ten times as many rows to find a match.
I don't suppose you have an index on ts_interval_start_time?
If not, what happens if you run these queries after adding one?
-Kevin