Shrirang Chitnis <Shrirang.Chitnis@xxxxxxxxxxxxxxx> writes: > Bryce, > The two queries are different: I suspect the second one is a typo and not what he really wanted. > WHERE (contexts.parent_key = 392210 > OR contexts.context_key IN > (SELECT collection_data.context_key > FROM collection_data > WHERE collection_data.collection_context_key = 392210) The only really effective way the planner knows to optimize an "IN (sub-SELECT)" is to turn it into a semi-join, which is not possible here because of the unrelated OR clause. You might consider replacing this with a UNION of two scans of "contexts". (And yes, I know it'd be nicer if the planner did that for you.) regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
