If you create an index like this: create index on foo(a,b,v) where d = some_constant;
there is no way to get an IOS on the index: you have to supply a the partial index exclusionary value to get the value of the index and that fools the IOS chooser because it doesn't see the value in the explicit list of index columns. The workaround is to include the 'partial value' (d) in the index, but often that's unnecessary. In other words, if you have a partial index that is based on a constant, a query that is filtering on the constant is an exception to the rule that all columns must be in the index to get the IOS. Not a bug, but it's worth noting. Aside: the performance gains I'm seeing for IOS are nothing short of spectacular. merlin -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
