Re: Slow query. Any way to speed up?

Patrick Hatcher <PHatcher(at)macys(dot)com> writes:
> -> Seq Scan on cdm_ddw_tran_item a1
> (cost=0.00..1547562.88 rows=8754773 width=23) (actual
> time=14.219..535704.691 rows=10838135 loops=1)
> Filter: ((((appl_id)::text = 'MCOM'::text)
> OR ((appl_id)::text = 'NET'::text)) AND ((tran_typ_id = 'S'::bpchar) OR
> (tran_typ_id = 'R'::bpchar)))

The bulk of the time is evidently going into this step. You didn't say
how big cdm_ddw_tran_item is, but unless it's in the billion-row range,
an indexscan isn't going to help for pulling out 10 million rows.
This may be about the best you can do :-(

If it *is* in the billion-row range, PG 8.1's bitmap indexscan facility
would probably help.

regards, tom lane