... One more thing: maybe we should rethink where to put
extraUpdatedCols. Between the facts that it's not used for
actual permissions checks, and that it's calculated by the
rewriter not parser, it doesn't seem like it really belongs
in RelPermissionInfo. Should we keep it in RangeTblEntry?
Should it go somewhere else entirely? I'm just speculating,
but now is a good time to think about it.
regards, tom lane