Horton

Re: row filtering for logical replication

Ajin Cherian <itsajin@gmail.com>

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From: Ajin Cherian <itsajin@gmail.com>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Euler Taveira <euler@eulerto.com>, Peter Smith <smithpb2250@gmail.com>, Rahila Syed <rahilasyed90@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Önder Kalacı <onderkalaci@gmail.com>, japin <japinli@hotmail.com>, Michael Paquier <michael@paquier.xyz>, David Steele <david@pgmasters.net>, Craig Ringer <craig@2ndquadrant.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Amit Langote <amitlangote09@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-10-12T02:33:12Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Release cache tuple when no longer needed

  2. Add some additional tests for row filters in logical replication.

  3. Fix one of the tests introduced in commit 52e4f0cd47.

  4. Allow specifying row filters for logical replication of tables.

  5. Move scanint8() to numutils.c

  6. Replace Test::More plans with done_testing

  7. Reduce relcache access in WAL sender streaming logical changes

  8. Small cleanups related to PUBLICATION framework code

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

  10. Allow publishing the tables of schema.

  11. Doc: improve documentation of CREATE/ALTER SUBSCRIPTION.

  12. Add PublicationTable and PublicationRelInfo structs

  13. Remove unused argument "txn" in maybe_send_schema().

  14. Add prepare API support for streaming transactions in logical replication.

  15. Unify PostgresNode's new() and get_new_node() methods

  16. Use l*_node() family of functions where appropriate

  17. Add support for prepared transactions to built-in logical replication.

  18. Restore the portal-level snapshot after procedure COMMIT/ROLLBACK.

  19. Rename a parse node to be more general

  20. Remove unused column atttypmod from initial tablesync query

  21. SEARCH and CYCLE clauses

On Tue, Oct 12, 2021 at 1:37 AM Dilip Kumar <dilipbalaut@gmail.com> wrote:
>
> On Wed, Oct 6, 2021 at 2:33 PM Ajin Cherian <itsajin@gmail.com> wrote:
> >
> > On Sat, Oct 2, 2021 at 5:44 PM Ajin Cherian <itsajin@gmail.com> wrote:
> > >
> > > I have for now also rebased the patch and merged the first 5 patches
> > > into 1, and added my changes for the above into the second patch.
> >
> > I have split the patches back again, just to be consistent with the
> > original state of the patches. Sorry for the inconvenience.
>
> Thanks for the updated version of the patch, I was looking into the
> latest version and I have a few comments.
>
>
> +        if ((att->attlen == -1 &&
> VARATT_IS_EXTERNAL_ONDISK(tmp_new_slot->tts_values[i])) &&
> +                (!old_slot->tts_isnull[i] &&
> +                    !(VARATT_IS_EXTERNAL_ONDISK(old_slot->tts_values[i]))))
> +        {
> +            tmp_new_slot->tts_values[i] = old_slot->tts_values[i];
> +            newtup_changed = true;
> +        }
>
> If the attribute is stored EXTERNAL_ONDIS on the new tuple and it is
> not null in the old tuple then it must be logged completely in the old
> tuple, so instead of checking
> !(VARATT_IS_EXTERNAL_ONDISK(old_slot->tts_values[i]), it should be
> asserted,
>
>
> +    heap_deform_tuple(newtuple, desc, new_slot->tts_values,
> new_slot->tts_isnull);
> +    heap_deform_tuple(oldtuple, desc, old_slot->tts_values,
> old_slot->tts_isnull);
> +
> +    if (newtup_changed)
> +        tmpnewtuple = heap_form_tuple(desc, tmp_new_slot->tts_values,
> new_slot->tts_isnull);
> +
> +    old_matched = pgoutput_row_filter(relation, NULL, oldtuple, entry);
> +    new_matched = pgoutput_row_filter(relation, NULL,
> +                                      newtup_changed ? tmpnewtuple :
> newtuple, entry);
>
> I do not like the fact that, first we have deformed the tuples and we
> are again using the HeapTuple
> for expression evaluation machinery and later the expression
> evaluation we do the deform again.
>
> So why don't you use the deformed tuple as it is to store as a virtual tuple?
>
> Infact, if newtup_changed is true then you are forming back the tuple
> just to get it deformed again
> in the expression evaluation.
>
> I think I have already given this comment on the last version.

Right, I only used the deformed tuple later when it was written to the
stream. I will modify this as well.

regards,
Ajin Cherian
Fujitsu Australia