Andres Freund <andres@2ndquadrant.com> writes:
> I think we also needs support for testing xid/multixid wraparound. It
> currently isn't realistically testable because of the timeframes
> involved.
When I've wanted to do that in the past, I've used pg_resetxlog to
adjust a cluster's counters. It still requires some manual hacking
though because pg_resetxlog isn't bright enough to create the new
pg_clog files needed when you move the xid counter a long way.
We could fix that, or we could make the backend more forgiving of
not finding the initial clog segment present at startup ...
regards, tom lane