Robert Haas <robertmhaas@gmail.com> writes:
> On Sat, Mar 3, 2012 at 10:03 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Sooner or later I'd like to relax the restriction that appendrel members
>> can't have extra WHERE clauses, but don't hold your breath waiting...
> Does this comment need updating?
> * Note: the data structure assumes that append-rel members are single
> * baserels. This is OK for inheritance, but it prevents us from pulling
> * up a UNION ALL member subquery if it contains a join. While that could
> * be fixed with a more complex data structure, at present there's not much
> * point because no improvement in the plan could result.
No, that's a different restriction.
regards, tom lane
