On 10/06/10 22:47, Craig James wrote:
Postgres normally doesn't index NULL values even if the column is indexed, so it has to do a table scan when your query includes an IS NULL condition.
That was addressed in version 8.3. 8.3 and upwards can use an index for IS NULL.
I believe the NULLs were stored in the index in earlier releases too, they just couldn't be searched for.
-- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
