Re: Two-phase commit issues

On Friday 20 May 2005 18:14, Tom Lane wrote:
> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > As I remember, you said two-phase wasn't 100% reliable and we just
> > needed a way to report failures.
>
> [ Shrug... ] I remain of the opinion that 2PC is a solution in search
> of a problem, because it does not solve the single point of failure
> issue (just moves same from the database to the 2PC controller).

You're right. 2PC to coordinate replicas of the same data is not that
interesting. It is however most interesting when coordination updates to
different objects such as (i) a central database server and a local staging
area or (ii) a database server and transactional queues in a workflow-style
app.

> But some people want it anyway, and they aren't going to be satisfied
> that we are an "enterprise grade" database until we can check off this
> particular bullet point. As long as the implementation doesn't impose
> any significant costs when not being used (which AFAICS Heikki's method
> doesn't), I think we gotta hold our noses and do it.

It is a definitly in the check list if you're shopping for a database to go
with your buzzword compliant J2EE app server. :-)

--
Jose Orlando Pereira