RE: Perform streaming logical transactions by background workers and parallel apply

On Sunday, January 8, 2023 11:59 AM houzj(dot)fnst(at)fujitsu(dot)com <houzj(dot)fnst(at)fujitsu(dot)com> wrote:
> On Sunday, January 8, 2023 10:14 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
> wrote:
> >
> > On Sat, Jan 7, 2023 at 2:25 PM Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
> > >
> >
> > Today, I was analyzing this patch w.r.t recent commit c6e1f62e2c and
> > found that
> > pa_set_xact_state() should set the latch (wake up) for the leader
> > worker as the leader could be waiting in pa_wait_for_xact_state().
> > What do you think? But otherwise, it should be okay w.r.t DDLs because
> > this patch allows the leader worker to restart logical replication for
> > subscription parameter change which will in turn stop/restart parallel workers
> if required.
>
> Thanks for the analysis. I agree that it would be better to signal the leader when
> setting the state to PARALLEL_TRANS_STARTED, otherwise it might slightly delay
> the timing of catch the state change in pa_wait_for_xact_state(), so I have
> updated the patch for the same. Besides, I also checked commit c6e1f62e2c, I
> think DDL operation doesn't need to wake up the parallel apply worker directly
> as the parallel apply worker doesn't start table sync and only communicate with
> the leader, so I didn't find some other places that need to be changed.
>
> Attach the updated patch set.

Sorry, the commit message of 0001 was accidentally deleted, just attach
the same patch set again with commit message.