Re: Two Phase Commit WAS: Re: Two weeks to feature freeze

Rod Taylor wrote:

>>Perhaps the people on this list who are pushing 2PC could do the ground work?
>
> - 2PC is better than a standard transaction when dealing with multiple
> servers as it can recover in some circumstances (but not all).
>
> - 2PC (XA support as described by the X/Open group) is the only
> implementation of distributed transactions supported by many third party
> components -- that I'm aware of -- to the point where it is a part of
> the Java Spec on dealing with distributed transactions.
>
> - 2PC isn't very good in a number of circumstances, as such PostgreSQL
> should avoid its use when PostgreSQL has a choice in the matter -- like
> communication with other PostgreSQL servers.
>
> This is a case of learning to speak Japanese because all of the people
> you want to talk with only speak Japanese. It simply doesn't matter how
> good Esperanto is.

I don't think it could have been said any better. There are a host of
improvements on the standard 2PC protocol, including 3PC, multi-cast
2PC, and other variants both synchronous and asynchronous. But if
PostgreSQL is going to work with XA, then it doesn't get to choose the
TM or the protocol. The only relevance of this thread, as I see it, is
whether or not core will stomach an XA-compatible 2PC implementation
in the backend. If not, then is Satoshi Nagayasu in vain? That was
what I "sensed" in the original thread 6 months ago, that the 2PC work
being done by Satoshi Nagayasu was going to be allowed to die on the vine.

Mike Mascari
mascarm(at)mascari(dot)com