I've got a table using a data type that I have created as the type for its primary key. I (hope) I have the type set up properly - it seems okay, and does not have any problem creating a b-tree index for the type. The problem I am having is that the index seems to never be chosen for use. I can force the use of the index by setting enable_seqscan to off. The table has about 1.2 million rows. I have also analyzed the table - and immediately afterwards there is no affect on the index's behaviour.