Re: 32/64-bit transaction IDs?

"Ed L." <pgsql@bluepolka.net> writes:
> I need a guaranteed ordering of transaction IDs as they are queued for
> asyncronous replication.  I'd use the 32-bit internal transaction ID from
> GetTransactionId(), but 32-bits will not suffice for the logic I'd like to
> use.  A 64-bit ID would work well enough.

Uh ... your replication logic cannot ensure to reach closure within two
billion transactions?  Something's pretty out of joint there.

> Further, I am uncertain those 32-bit transaction IDs represent a correctly
> ordered sequence of transactions.

XIDs are issued in transaction start order, not transaction commit
order.  Dunno if that's what's concerning you.

            regards, tom lane