On Sun, Feb 8, 2009 at 6:34 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> It's possible that there are specific cases where the UNION optimization
> checks could allow domains to be treated as their base types, but
> blindly smashing both sides of the check to base is going to break more
> cases than it fixes.
What my little patch was trying to proof, is whether, that part of
planner could construct the plan better, if it had a notion of base
type in domains.
Which I still believe it should do, based on my simple test.
Again, I am not saying, that postgresql should treat domains just as
an alias to base type, but I do believe that it should at least
construct plan better - based on the base type, not the domain's oid.
If you know what it might possibly break, can you give some examples please ?
--
GJ