|Subject||Re: [firebird-support] slow to find nulls despite index|
> Try creating a descending index on that column, then run set stats on both itand the ascending index; after that, test for the null case. Note both the plan
and the performance. The optimizer should choose the new index (if it thinks it
would be useful), use an all-natural plan (middle way) or (worst) stick with the
(bad) ascending index.
>You rock. That totally fixed the problem. I did have to drop the ascending
indices first, but then it picked the descending, and improved significantly.