On 18 July 2012 17:10, Nick Hofstede <Nick.Hofstede@xxxxxxxxxxxxxxxxxx> wrote: > Hi, > > I'm surprised at the difference in speed/execution plan between two logically equivalent queries, one using IN, the other using EXISTS. (At least I think they are logically equivalent) They are not logically equivalent. http://www.postgresql.org/docs/current/static/functions-subquery.html See the notes about NULL under IN. -- Peter Geoghegan http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training and Services -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
