> stats=# explain analyze SELECT work_units, min(raw_rank) AS rank FROM Trank_work_overall GROUP BY work_units;
>
> ...
>
> raw_rank | bigint |
> work_units | bigint |
If you create a copy of the same table using regular integers does that run
fast? And a copy of the table using bigints is still slow like the original?
I know bigints are less efficient than integers because they're handled using
dynamically allocated memory. This especially bites aggregate functions. But I
don't see why it would be any slower for a hash aggregate than a regular
aggregate. It's a pretty gross amount of time for 18k records.
There was a thought a while back about making 64-bit machines handle 64-bit
datatypes like bigints without pointers. That would help on your Opteron.
--
greg
