Re: Commit Timestamp and LSN Inversion issue

On Thu, Nov 7, 2024 at 9:39 PM Jan Wieck <jan(at)wi3ck(dot)info> wrote:
>
> On 11/6/24 21:30, Zhijie Hou (Fujitsu) wrote:
> >
> > Thanks for the patch! I am reading the patch and noticed few minor things.
> >
> > 1.
> > + /*
> > + * This is a local transaction. Make sure that the xact_time
> > + * higher than any timestamp we have seen thus far.
> > + *
> > + * TODO: This is not postmaster restart safe. If the local
> > + * system clock is further behind other nodes than it takes
> > + * for the postmaster to restart (time between it stops
> > + * accepting new transactions and time when it becomes ready
> > + * to accept new transactions), local transactions will not
> > + * be bumped into the future correctly.
> > + */
> >
> > The TODO section mentions other nodes, but I believe think patch currently do
> > not have the handling of timestamps for other nodes. Should we either remove
> > this part or add a brief explanation to clarify the relationship with other
> > nodes?
>
> That TODO is actually obsolete. I understood from Amit Kapila that the
> community does assume that NTP synchronization is good enough.
>

This is my understanding from the relevant discussion in the email thread [1].

[1] - https://www.postgresql.org/message-id/2423650.1726842094%40sss.pgh.pa.us
--
With Regards,
Amit Kapila.