RE: Really SLOW using GROUP BY ...!?

> I beg your pardon?

Get it - I didn't know about enable_seqscan -:)

> Unfortunately neither of these plans is likely to be especially speedy
> on ~3 million rows.  The index scan will just thrash the disk, unless
> the table has been clustered recently --- and given the
> deficiencies of our CLUSTER implementation, I'd hesitate to recommend
> using it.

Easy to try - why don't do.

> I have a personal TODO item to see about implementing group +
> aggregate with a hash table of active aggregate values, per a
> suggestion recently from devik@cdi.cz.  That would allow this
> query to be done with a sequential scan and no sort, which is
> probably what Oracle is doing. Won't happen for 7.1 though ...

Well, definitely good approach. But for the moment increasing
sort memory is only hope and it should help.

Vadim