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From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Date: Fri, 22 Apr 2022 21:39:24 +0530
Message-ID: <CALj2ACVOzhs+BD+abFV2x4oKJdsDNd6SgsE7r8UjnZDCKGEckA@mail.gmail.com>
Subject: Re: Skipping schema changes in publication
To: vignesh C <vignesh21@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
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On Tue, Mar 22, 2022 at 12:39 PM vignesh C <vignesh21@gmail.com> wrote:
>
> Hi,
>
> This feature adds an option to skip changes of all tables in specified
> schema while creating publication.
> This feature is helpful for use cases where the user wants to
> subscribe to all the changes except for the changes present in a few
> schemas.
> Ex:
> CREATE PUBLICATION pub1 FOR ALL TABLES SKIP ALL TABLES IN SCHEMA s1,s2;
> OR
> ALTER PUBLICATION pub1 ADD SKIP ALL TABLES IN SCHEMA s1,s2;
>
> A new column pnskip is added to table "pg_publication_namespace", to
> maintain the schemas that the user wants to skip publishing through
> the publication. Modified the output plugin (pgoutput) to skip
> publishing the changes if the relation is part of skip schema
> publication.
> As a continuation to this, I will work on implementing skipping tables
> from all tables in schema and skipping tables from all tables
> publication.
>
> Attached patch has the implementation for this.
> This feature is for the pg16 version.
> Thoughts?

The feature seems to be useful especially when there are lots of
schemas in a database. However, I don't quite like the syntax. Do we
have 'SKIP' identifier in any of the SQL statements in SQL standard?
Can we think of adding skip_schema_list as an option, something like
below?

CREATE PUBLICATION foo FOR ALL TABLES (skip_schema_list = 's1, s2');
ALTER PUBLICATION foo SET (skip_schema_list = 's1, s2'); - to set
ALTER PUBLICATION foo SET (skip_schema_list = ''); - to reset

Regards,
Bharath Rupireddy.