On Fri, 21 May 2010, Richard Yen wrote:
Any ideas why the query planner chooses a different query plan when using prepared statements?
This is a FAQ. Preparing a statement makes Postgres create a plan, without knowing the values that you will plug in, so it will not be as optimal as if the values were available. The whole idea is to avoid the planning cost each time the query is executed, but if your data is unusual it can result in worse plans.
Matthew -- Existence is a convenient concept to designate all of the files that an executable program can potentially process. -- Fortran77 standard -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
