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

On Fri, Sep 9, 2022 at 2:31 PM houzj(dot)fnst(at)fujitsu(dot)com
<houzj(dot)fnst(at)fujitsu(dot)com> wrote:
>
> On Friday, September 9, 2022 3:02 PM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
> >
>
> > 3.
> >
> > max_logical_replication_workers (integer)
> > Specifies maximum number of logical replication workers. This
> > includes apply leader workers, parallel apply workers, and table
> > synchronization workers.
> > Logical replication workers are taken from the pool defined by
> > max_worker_processes.
> > The default value is 4. This parameter can only be set at server start.
> >
> > ~
> >
> > I did not really understand why the default is 4. Because the default
> > tablesync workers is 2, and the default parallel workers is 2, but
> > what about accounting for the apply worker? Therefore, shouldn't
> > max_logical_replication_workers default be 5 instead of 4?
>
> The parallel apply is disabled by default, so it's not a must to increase this
> global default value as discussed[1]
>
> [1] https://www.postgresql.org/message-id/CAD21AoCwaU8SqjmC7UkKWNjDg3Uz4FDGurMpis3zw5SEC%2B27jQ%40mail.gmail.com
>

Okay, but can we document to increase this value when the parallel
apply is enabled?

--
With Regards,
Amit Kapila.