On 3/13/15 7:12 PM, Tomas Vondra wrote:
(4) I suspect many of the relations referenced in the views are not
actually needed in the query, i.e. the join is performed but
then it's just discarded because those columns are not used.
Try to simplify the views as much has possible - remove all the
tables that are not really necessary to run the query. If two
queries need different tables, maybe defining two views is
a better approach.
A better alternative with multi-purpose views is to use an outer join
instead of an inner join. With an outer join if you ultimately don't
refer to any of the columns in a particular table Postgres will remove
the table from the query completely.
--
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com
--
Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance
