Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
> This sounds like extending Xid to 64 bits, without having to store the
> high bits everywhere. Was this discussed in the PGCon devs meeting?
Yeah, that's what it would amount to. It was not discussed at the dev
meeting --- it was an idea that came up one evening at PGCon.
I'm not sure whether this would imply having to widen xid to 64 bits
internally. That could be a bit unpleasant as far as CPU and shared
memory space go, although every year that goes by makes 32-bit machines
less interesting as DB servers.
regards, tom lane