Re: planner/optimizer question

Manfred Koizar <mkoi-pg@aon.at> writes:
> Yes, the visible-to-all flag would be set as a by-product of an index
> scan, if the heap tuple is found to be visible to all active
> transactions.  This update is non-critical

Oh really?  I think you need to think harder about the transition
conditions.

Dead-to-all is reasonably safe to treat as a hint bit because *it does
not ever need to be undone*.  Visible-to-all does not have that
property.

            regards, tom lane