Alvaro Herrera wrote:
> I'm thinking about the comparison of full infomask as you propose
> instead of just the bits that we actually care about. I think the only
> thing that could cause a spurious failure (causing an extra execution of
> the HeapTupleSatisfiesUpdate call and the stuff below) is somebody
> setting HEAP_XMIN_COMMITTED concurrently; but that seems infrequent
> enough that it should pretty harmless. However, should we worry about
> possible future infomask bit changes that could negatively affect this
> behavior?
Here's a complete patch illustrating what I mean. This is slightly more
expensive than straight infomask comparison in terms of machine
instructions, but that seems okay to me.
--
Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
