Re: cascading column drop to index predicates

Rod Taylor <pg@rbt.ca> writes:
> I think Andreas is trying to argue that if you drop column b from index
> (a, b) that the index should be converted into index(a) -- assuming of
> course there isn't already an index(a).

That seems to be well outside the charter of DROP CASCADE.  I think we
either drop or don't drop; we don't go building new indexes, which is
what this would take.  There are also definitional problems --- for
instance, if the index is UNIQUE, does it transmogrify into a UNIQUE
constraint on A alone (which would most likely fail)?
        regards, tom lane