Re: queries stop using indexes

On lau, 2007-03-31 at 18:51 -0400, Jonathan Vanasco wrote:
> I have a table with 15 cols , there is an joint index on 5 of them
>
> there are ~15million records in the table, and it gets heavy use via
> update & insert
>
> i recently noticed that after a day of use, the index is no longer
> being respected in some/all queries and a seq scan on the table is used
>
> i ran analyze, no change.
> i ran vacuum analyze, no change.
>
> i dropped the index, and recreated it -- its now used again.

if you analyze the table after recreating the index, does it then stop
using it?

possibly you need to increase statistic targets on some or all
of the index columns.

a EXPLAIN ANALYZE could help figuring this out.

gnari