index selection by query planner

Started by Rohit Gaddiover 20 years ago2 messages
#1Rohit Gaddi
rohitgaddi@yahoo.co.in

Hi,

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.

Thanks,
Rohit

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#2Josh Berkus
josh@agliodbs.com
In reply to: Rohit Gaddi (#1)
Re: index selection by query planner

Rohit,

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.

Please post the query, the table and index definitions, and the EXPLAIN
ANALYZE to the PGSQL-PERFORMANCE mailing list. Thanks!

--
Josh Berkus
Aglio Database Solutions
San Francisco