Re: Postgres XA support

Ludovic Orban wrote:
> From the comments I saw in the source, transaction interleaving, join
> and suspend/resume are still not supported and forget is still
> unimplemented. This means you cannot mix local and global
> transactions, cannot support EJBs with REQUIRES_NEW CMT declaration
> and can get into troubles during crash recovery.
>
> I think it was Michael Allman that said the engine wasn't able to
> properly support XA in Aug 2005 and unfortunately it seems that things
> haven't changed much since then.
>
> I'm afraid you still have some work to do on the engine before you can
> implement XA in JDBC.

Well there are two perspectives on this. If you need a way of
implementing multi-resource transactions, than the simple two phase
commit approach implemented in postgresql is adequate. If full XA
compliance is required then postgresql comes up far short. Yes, backend
development has stalled on this. Backend developers were not aware of
the full XA requirements and when informed said, "We implemented all
this two phase stuff and now you're telling us it's inadequate!" So
they've moved on and the ability to do things like transaction
interleaving are very complicated given the postgresql backend model, so
I wouldn't hold my breath on things changing anytime soon.

Kris Jurka