Kevin Grittner <kgrittn@ymail.com> writes:
> Are we talking about the probe for the end (or beginning) of an
> index?  If so, should we even care about visibility of the row
> related to the most extreme index entry?  Should we even go to the
> heap during the plan phase?
Consider the case where some transaction inserted a wildly out-of-range
value, then rolled back.  If we don't check validity of the heap row,
we'd be using that silly endpoint value for planning purposes ---
indefinitely.  That's not an improvement over the situation that the
probe is meant to fix.
            regards, tom lane