Re: Using IN with subselect

That's what I wanted it to do I just did not understand how to read the
explain. So is it HashAggregate that means this already loaded?

On Thu, 2004-11-25 at 12:57, Tom Lane wrote:
> Dave Smith <dave(dot)smith(at)candata(dot)com> writes:
> > Well here is explain. I would guess that it is executed each time ..
> > function any different?
>
> > HashAggregate (cost=288.32..288.32 rows=1 width=32)
> > -> Hash IN Join (cost=288.18..288.31 rows=1 width=32)
> > -> Subquery Scan journal_all (cost=282.36..282.45 rows=2 width=64)
> > -> Hash (cost=5.83..5.83 rows=1 width=13)
> > -> Index Scan using glmast_index3 on glmast (cost=0.00..5.83 rows=1 width=13)
>
> No ... this plan says to scan glmast once, load the selected rows into
> an in-memory hash table, then scan journal_all once and probe the hash
> table for matches. It looks like a pretty decent choice of plan to me.
>
> regards, tom lane
--
Dave Smith
CANdata Systems Ltd
416-493-9020