Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> writes:
> I am working on Grouping Sets support. The first issue is "cube"
> keyword. Contrib module "cube" define a few functions "cube". So if we
> want to continue in support this function, then "cube" have to be a
> unreserved keyword. But then we have a gram conflict with mentioned
> obsolete syntax. I am thinking so after removing add_missing_from this
> syntax is useless. Without this feature we can clean a gramatic.
That's a documented and useful feature. It's not going away. Even
if it did go away, removing it wouldn't do a thing to solve grammar
problems, because the grammar isn't involved in that.
regards, tom lane