Re: logical decoding of two-phase transactions

On 2017-02-03 19:09:43 -0500, Robert Haas wrote:
> On Fri, Feb 3, 2017 at 7:08 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:
> > On 2017-02-03 18:47:23 -0500, Robert Haas wrote:
> >> On Fri, Feb 3, 2017 at 6:00 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:
> >> > I still haven't seen a credible model for being able to apply a stream
> >> > of interleaved transactions that can roll back individually; I think we
> >> > really need the ability to have multiple transactions alive in one
> >> > backend for that.
> >>
> >> Hmm, yeah, that's a problem. That smells like autonomous transactions.
> >
> > Unfortunately the last few proposals, like spawning backends, to deal
> > with autonomous xacts aren't really suitable for replication, unless you
> > only have very large ones. And it really needs to be an implementation
> > where ATs can freely be switched inbetween. On the other hand, a good
> > deal of problems (like locking) shouldn't be an issue, since there's
> > obviously a possible execution schedule.
> >
> > I suspect this'd need some low-level implemention close to xact.c that'd
> > allow switching between transactions.
>
> Yeah. Well, I still feel like that's also how autonomous transactions
> oughta work, but I realize that's not a unanimous viewpoint. :-)

Same here ;)