Re: Transactions involving multiple postgres foreign servers, take 2

On Fri, May 21, 2021 at 5:48 PM Masahiro Ikeda <ikedamsh@oss.nttdata.com> wrote:
>
>
>
> On 2021/05/21 13:45, Masahiko Sawada wrote:
> >
> > Yes. We also might need to be careful about the order of foreign
> > transaction resolution. I think we need to resolve foreign> transactions in arrival order at least within a foreign
server.
>
> I agree it's better.
>
> (Although this is my interest...)
> Is it necessary? Although this idea seems to be for atomic visibility,
> 2PC can't realize that as you know. So, I wondered that.

I think it's for fairness. If a foreign transaction arrived earlier
gets put off so often for other foreign transactions arrived later due
to its index in FdwXactCtl->xacts, it’s not understandable for users
and not fair. I think it’s better to handle foreign transactions in
FIFO manner (although this problem exists even in the current code).

Regards,

--
Masahiko Sawada
EDB:  https://www.enterprisedb.com/