Reece,
> When I add a simple predicate based on an indexed column to a query (Q1,
> below), the query becomes much slower (Q2). This is despite a
> multi-column index that in principle ought to have greatly improved
> performance. When I remove the multi-column index, the query plan for
> Q2 reverts to using the same index as that for Q1.
How large is that mutli-colum index? Disk size? How much RAM do you
have?
--
--Josh
Josh Berkus
PostgreSQL @ Sun
San Francisco