Horton

Re: Skipping logical replication transactions on subscriber side

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>, "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>, vignesh C <vignesh21@gmail.com>, Greg Nancarrow <gregn4422@gmail.com>, "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>, Alexey Lesovsky <lesovsky@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>, "osumi.takamichi@fujitsu.com" <osumi.takamichi@fujitsu.com>
Date: 2022-01-25T02:54:45Z
Lists: pgsql-hackers 
On Mon, Jan 24, 2022 at 7:36 PM Peter Eisentraut
<peter.eisentraut@enterprisedb.com> wrote:
>
> On 22.01.22 03:54, Amit Kapila wrote:
> > Won't we already do that for Alter Subscription command which means
> > nothing special needs to be done for this? However, it seems to me
> > that the idea we are trying to follow here is that as this option can
> > lead to data inconsistency, it is good to allow only superusers to
> > specify this option. The owner of the subscription can be changed to
> > non-superuser as well in which case I think it won't be a good idea to
> > allow this option. OTOH, if we think it is okay to allow such an
> > option to users that don't have superuser privilege then I think
> > allowing it to the owner of the subscription makes sense to me.
>
> I don't think this functionality allows a nonprivileged user to do
> anything they couldn't otherwise do.  You can create inconsistent data
> in the sense that you can choose not to apply certain replicated data.
>

I thought this will be the only primary way to skip applying certain
transactions. The other could be via pg_replication_origin_advance().
Or are you talking about the case where we skip applying update/delete
where the corresponding rows are not found?

I see the point that if we can allow the owner to skip applying
updates/deletes in certain cases then probably this should also be
okay. Kindly let us know if you have something else in mind as well?

-- 
With Regards,
Amit Kapila.

Commits

  1. Test ALIGNOF_DOUBLE==4 compatibility under ALIGNOF_DOUBLE==8.

  2. Reorder subskiplsn in pg_subscription to avoid alignment issues.

  3. Add ALTER SUBSCRIPTION ... SKIP.

  4. Optionally disable subscriptions on error.

  5. Update docs of logical replication for commit 8d74fc96db.

  6. Respect permissions within logical replication.

  7. Fix regression test failure caused by commit 8d74fc96db.

  8. Add a view to show the stats of subscription workers.

  9. Add logical change details to logical replication worker errcontext.

  10. Rename LOGICAL_REP_MSG_STREAM_END to LOGICAL_REP_MSG_STREAM_STOP.

  11. Fix typo in protocol.sgml.

  12. Remove unused argument in apply_handle_commit_internal().

  13. Fix replication of in-progress transactions in tablesync worker.

  14. Reorder pg_sequence columns to avoid alignment issue