Re: Challenges preventing us moving to 64 bit transaction id (XID)?

On Fri, Mar 2, 2018 at 12:07 AM Andres Freund <andres(at)anarazel(dot)de> wrote:

> On 2018-03-02 01:56:00 +0300, Alexander Korotkov wrote:
> > On Fri, Mar 2, 2018 at 1:51 AM, Andres Freund <andres(at)anarazel(dot)de>
> wrote:
> >
> > > On 2018-03-02 01:48:03 +0300, Alexander Korotkov wrote:
> > > > Also, the last commitfest is already too late for such big changes.
> > > > So, I'm marking this RWF.
> > >
> > > Agreed. Perhaps extract the 64bit GUC patch and track that separately?
> > > Seems like something we should just do...
> > >
> >
> > Sounds reasonable. But I didn't notice if there are other users for
> 64bit
> > GUCs besides 64bit xids?
>
> I think there were a couple past occasions where we could've used that,
> don't quite recall the details. We're at least not that far away from
> the point where various size limits are actually limited by int32
> range. And timeouts of ~25 days are long but not entirely unreasonable.
>

As a note here, I have worked on projects where there could be 2-week-long
idle-in-transaction states (no joke, we tuned things to only use virtual
xids for most of that time), and having an ability to set
idle-in-transaction timeouts to figures of greater than a month are things
I could imagine doing. I would certainly favor the idea of 64-big GUC
variables as a general rule.

>
> Greetings,
>
> Andres Freund
>
>

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