Re: Logical replication support for generic wal record

On Mon, 22 Aug 2022 at 12:16, Bharath Rupireddy <
bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote:

> On Mon, Aug 22, 2022 at 11:59 AM Natarajan R <nataraj3098(at)gmail(dot)com>
> wrote:
> >
> > Hi All,
> >
> > I am writing a postgres extension which writes only generic wal record,
> but this wal is not recognized by logical replication decoder. I have a
> basic understanding of how logical replication(COPY command for initial
> sync, wal replica for final sync) works, can you please tell us a way to
> support this?
>
> "Generic" resource manager doesn't have a decoding API, see [1], which
> means that the generic WAL records will not get decoded.
>
> Can you be more specific about the use-case? Why use only "Generic"
> type WAL records? Why not use "LogicalMessage" type WAL records if you
> want your WAL records to be decoded?
>
> I am writing an extension which implements postgres table access method
interface[1] with master-slave architecture, with the help of doc[1] i
decided to go with generic_wal to achieve crash_safety and also for
streaming replication. It seems like generic_wal couldn't help with logical
replication..
But, I don't have knowledge on "LogicalMessage" Resource Manager, need to
explore about it.

[1] https://www.postgresql.org/docs/current/tableam.html