Re: Usage of epoch in txid_current

Stephen Frost <sfrost@snowman.net> writes:
> * Andres Freund (andres@anarazel.de) wrote:
>> I kinda wonder if we shouldn't just track nextXid as a 64bit integer
>> internally, instead of bothering with tracking the epoch
>> separately. Then we can "just" truncate it in the cases where it's
>> stored in space constrained places etc.

> This sounds reasonable to me, at least, but I've not been in these
> depths much.

+1 ... I think the reason it's like that is simply that nobody's revisited
the XID generator since we decided to require 64-bit integer support.

We'd need this for support of true 64-bit XIDs, too, though I'm unsure
whether that project is going anywhere anytime soon.  In any case it
seems like a separable subset of that work.

            regards, tom lane