Re: PostgreSQL Logical decoding

Thanks Ashutosh,

Actually we use the Postgres service offered by Azure (Flexible server).
So, I was looking at the following documentation which talks about Logical
Replication and Logical Decoding as two different methods of replication.
Here Logical replication talks about creating both Publisher and Subscriber
settings using simple SQL statements. While for Logical decoding its
talking about publishing WAL but not on how to consume this WAL.
Logical replication and logical decoding - Azure Database for PostgreSQL -
Flexible Server | Microsoft Learn
<https://learn.microsoft.com/en-us/azure/postgresql/flexible-server/concepts-logical>

Also Logical Replication has some limitations like materialized views,
sequences being not replicated. While DDL changes propagation is a common
deficiency among both Logical decoding and Logical Replication. Am I
reading this correctly?
PostgreSQL: Documentation: 12: 30.4. Restrictions
<https://www.postgresql.org/docs/12/logical-replication-restrictions.html>

With this reading I thought Logical decoding may be the way to go. However
please guide us on our understanding.

Thanks
Ankit

On Tue, Oct 11, 2022 at 11:01 AM Ashutosh Bapat <
ashutosh(dot)bapat(dot)oss(at)gmail(dot)com> wrote:

> Hi Ankit,
>
>
> On Tue, Oct 11, 2022 at 9:32 AM Ankit Oza <ankit(dot)p(dot)oza(at)gmail(dot)com> wrote:
> >
> > Hello,
> >
> > We are looking for an example on how to consume the changes of WAL
> produced by logical decoding (streaming or SQL interface) in another
> postgres server.
>
> built-in logical replication is good example to start looking for.
> https://www.postgresql.org/docs/current/logical-replication.html
>
> >
> > Basically, we are trying to create a replica/standby postgre server to a
> primary progre server. Between Logical replication and Logical Decoding we
> came up with Logical decoding as the choice due to limitation of logical
> replication (materialized views, external views/tables, sequences not
> replicated). However we are not finding a good example with instructions on
> how to set up a consumer postgre server.
> >
>
> Logical decoding is the process to convert WAL to a logical change,
> logical replication deals with transferring these changes to another
> server and applying those there. So they work in tandem; just one
> without the other can not be used. So I am confused about your
> requirements.
>
> --
> Best Wishes,
> Ashutosh Bapat
>