Horton

Re: Skipping logical replication transactions on subscriber side

Greg Nancarrow <gregn4422@gmail.com>

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From: Greg Nancarrow <gregn4422@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>, "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>, "osumi.takamichi@fujitsu.com" <osumi.takamichi@fujitsu.com>, Alexey Lesovsky <lesovsky@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2021-10-26T08:57:32Z
Lists: pgsql-hackers 
On Tue, Oct 26, 2021 at 5:16 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> I agree that we will need a separate syntax for conflict resolution
> but there is some similarity in what I proposed above (On
> Error/Conflict [1]) with the existing syntax of Insert ... On
> Conflict. I understand that here the context is different and we are
> storing this information in the catalog but still there is some syntax
> similarity and it will avoid adding new syntax variants.
>

The problem I see with the suggested syntax:

Alter Subscription <sub_name> On Error ( subscription_parameter [=
value] [, ... ] );
OR
Alter Subscription <sub_name> On Conflict ( subscription_parameter [=
value] [, ... ] );

is that "On Error ..." and "On Conflict" imply an action to be done on
a future condition (Error/Conflict), whereas at least in this case
(skip_xid) it's only AFTER the problem condition has occurred that we
know the XID of the failed transaction that we want to skip. So that
syntax looks a little confusing to me. Unless you had something else
in mind on how it would work?

Regards,
Greg Nancarrow
Fujitsu Australia

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