On Wed, Mar 9, 2011 at 6:01 PM, Jim Nasby <jim@xxxxxxxxx> wrote: > Unfortunately, I don't think the planner actually has that level of knowledge. Actually, I don't think it would be that hard to teach the planner about that special case... > A more reasonable fix might be to teach the executor that it can do 2 scans of the index: one to get non-null data and a second to get null data. I don't know if the use case is prevalent enough to warrant the extra code though. That would probably be harder, but useful. I thought about working on it before but got sidetracked onto other things. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
