Horton

Re: row filtering for logical replication

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Euler Taveira <euler@eulerto.com>
Cc: 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: 2021-09-01T12:36:00Z
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 Wed, Sep 1, 2021 at 4:53 PM Euler Taveira <euler@eulerto.com> wrote:
>
> On Sun, Aug 29, 2021, at 11:14 PM, Peter Smith wrote:
>
> Here are the new v26* patches. This is a refactoring of the row-filter
> caches to remove all the logic from the get_rel_sync_entry function
> and delay it until if/when needed in the pgoutput_row_filter function.
> This is now implemented per Amit's suggestion to move all the cache
> code [1]. It is a replacement for the v25* patches.
>
> The make check and TAP subscription tests are all OK. I have repeated
> the performance tests [2] and those results are good too.
>
> v26-0001 <--- v23 (base RF patch)
> v26-0002 <--- ExprState cache mods (refactored row filter caching)
> v26-0002 <--- ExprState cache extra debug logging (temp)
>
> Peter, I'm still reviewing this new cache mechanism. I will provide a feedback
> as soon as I integrate it as part of this recent modification.
>
> I'm attaching a new version that simply including Houzj review [1]. This is
> based on v23.
>
> There has been a discussion about which row should be used by row filter. We
> don't have a unanimous choice, so I think it is prudent to provide a way for
> the user to change it. I suggested in a previous email [2] that a publication
> option should be added. Hence, row filter can be applied to old tuple, new
> tuple, or both. This approach is simpler than using OLD/NEW references (less
> code and avoid validation such as NEW reference for DELETEs and OLD reference
> for INSERTs). I think about a reasonable default value and it seems _new_ tuple
> is a good one because (i) it is always available and (ii) user doesn't have
> to figure out that replication is broken due to a column that is not part
> of replica identity.
>

I think this or any other similar solution for row filters (on
updates) won't work till we solve the problem reported by Hou-San [1].
The main reason is that we don't have data for unchanged toast columns
in WAL. For that, we have discussed some probable solutions in email
[2], however, that also required us to solve one of the existing
bugs[3].

[1] - https://www.postgresql.org/message-id/OS0PR01MB571618736E7E79309A723BBE94E99%40OS0PR01MB5716.jpnprd01.prod.outlook.com
[2] - https://www.postgresql.org/message-id/CAA4eK1JLQqNZypOpN7h3%3DVt0JJW4Yb_FsLJS%3DT8J9J-WXgFMYg%40mail.gmail.com
[3] - https://www.postgresql.org/message-id/OS0PR01MB611342D0A92D4F4BF26C0F47FB229@OS0PR01MB6113.jpnprd01.prod.outlook.com

-- 
With Regards,
Amit Kapila.