Re: Exposing the Xact commit order to the user

Jan Wieck <JanWieck@Yahoo.com> wrote:
> I actually have a hard time understanding why people are so
> opposed to a feature that has zero impact at all unless a DBA
> actually turns in ON.  What is the problem with exposing the
> commit order of transactions?
FWIW, once I came to understand the use case, it seems to me a
perfectly reasonable and useful thing to have.  It does strike me
that there may be value to add one more xid to support certain
types of integrity for some use cases, but that's certainly
something which could be added later, if at all.  Once I realized
that, I just dropped out of the discussion; perhaps I should have
bowed out with an endorsement.
Unless my memory is failing me worse than usual, Dan Ports, who is
working on the serializable implementation so he can use the
predicate locking with a transaction-aware caching feature, needs
the ability to track commit order of transactions by xid; so the use
cases go beyond Slony and Londiste.
-Kevin