Re: Typmod associated with multi-row VALUES constructs

​The merit of "won't back-patch"​ is that at least you don't punish those who are being lazy (in a good sense) but generating values in subsequent lines that conform to the type specification of the first record.  We already implicitly accept such behavior elsewhere - though probably with better validation - so keeping it here is defense-able.  We dislike changing query plans in back branches and this really isn't that different.

The concern, especially since this can propagate to a CREATE TABLE AS, is whether there is some kind of fundamental storage risk being introduced that we do not want to have happen no matter how rare.  /me feels deja-vu...

David J.