Tom Lane writes:
> "Dave Golombek" <daveg@blackducksoftware.com> writes:
> > Is there a way I can reformulate the query to help the planner use the
> > indices?
>
> Use 8.2. Also put an index on the base table, not only the children ---
> the forced seqscan on the base weighs down the cost estimate for the
> plan you would like to have. (With sufficiently large child tables,
> that might not matter, but it sure does for this toy example.)
Ah, I forgot to try the index on the base table using 8.2, which does indeed
solve the problem. It unfortunately doesn't help with 8.1.4, which we have
in the field; any thoughts on workarounds for older versions or should I
just use a function until we can upgrade everywhere? We have 150 million
rows spread across 16 child tables, which should help cost estimation.
Thanks,
Dave