Alex Pilosov <alex@pilosoft.com> writes:
>> At some point it'd be nice to use type-specific hash functions for
>> hashjoin --- we support 'em for hash indexes, and I don't see why the
>> join mechanism should not use the same functions. With that, it'd be
>> possible to overcome this problem by making a hash function that has
>> the same blind spots as the comparison function ...
> I guess the idea is to add a hash function to a catalog of a type
> definition is a good idea?
Either that, or replace the oprcanhash boolean field of pg_operator
by an OID field that links to the appropriate hash function. Not sure
offhand which is better.
regards, tom lane