Re: Index isn't used during a join.

When grilled further on (Mon, 9 Jan 2006 22:58:18 -0700),
Michael Fuhr <mike(at)fuhr(dot)org> confessed:

> On Mon, Jan 09, 2006 at 09:23:38PM -0700, Robert Creager wrote:
> > I'm working with a query to get more info out with a join. The base
> > query works great speed wise because of index usage. When the join is
> > tossed in, the index is no longer used, so the query performance tanks.
>
> The first query you posted returns 285 rows and the second returns
> over one million; index usage aside, that difference surely accounts
> for a performance penalty. And as is often pointed out, index scans
> aren't always faster than sequential scans: the more of a table a
> query has to fetch, the more likely a sequential scan will be faster.

Thanks for pointing out the obvious that I missed. Too much data in the second query. It's supposed to match (row wise) what was returned from the first query.

Just ignore me for now...

Thanks,
Rob

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