Rohit Gaddi <[EMAIL PROTECTED]> writes:
> I have a table with two indices on the same column, one of which is a partial
> index. I would like the query planner to use the partial index whenever the
> query condition lies in the range of the partial index as it would yield
> better performance. Is there any way to enforce the ordering for the indices?
> How does the query planner decide which index to use when a particular query
> is fired? 'Explain Analyze' showed the total index being used in a situation
> that could be fulfiled by the partial index.
When you're asking this sort of question you should actually *show* the
EXPLAIN ANALYZE results. I would also suggest showing the comparison
to the other plan, which you can get in a nondestructive way like this:
EXPLAIN ANALYZE .... ;
-- plan using total index here
BEGIN;
DROP INDEX total_index;
EXPLAIN ANALYZE .... ;
-- plan using partial index here, we hope
ROLLBACK;
Also, this is really on-topic for pgsql-performance, not either of the
two lists you have chosen.
regards, tom lane
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