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Re: Column Filtering in Logical Replication

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Justin Pryzby <pryzby@telsasoft.com>, "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>, Rahila Syed <rahilasyed90@gmail.com>, Peter Smith <smithpb2250@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-02-16T10:05:34Z
Lists: pgsql-hackers 
On Wed, Feb 16, 2022 at 5:03 AM Tomas Vondra
<tomas.vondra@enterprisedb.com> wrote:
>
> Hi,
>
> Here's an updated version of the patch, rebased to current master. Parts
> 0002 and 0003 include various improvements based on review by me and
> another one by Peter Smith [1].
>
> Part 0003 reworks and significantly extends the TAP test, to exercise
> various cases related to changes of replica identity etc. discussed in
> this thread. Some of the tests however still fail, because the behavior
> was not updated - I'll work on that once we agree what the expected
> behavior is.
>
> 1) partitioning with pubviaroot=true
>
> The main set of failures is related to partitions with different replica
> identities and (pubviaroot=true), some of which may be mismatching the
> column list. There are multiple such test cases, depending on how the
> inconsistency is introduced - it may be there from the beginning, the
> column filter may be modified after adding the partitioned table to the
> publication, etc.
>
> I think the expected behavior is to prohibit such cases from happening,
> by cross-checking the column filter when adding the partitioned table to
> publication, attaching a partition or changing a column filter.
>

I feel it is better to follow the way described by Peter E. here [1]
to handle these cases. The row filter patch is also using the same
scheme as that is what we are doing now for Updates/Deletes and it
would be really challenging and much more effort/code to deal with
everything at DDL time. I have tried to explain some of that in my
emails [2][3].

[1] - https://www.postgresql.org/message-id/ca91dc91-80ba-e954-213e-b4170a6160f5%40enterprisedb.com
[2] - https://www.postgresql.org/message-id/CAA4eK1%2Bm45Xyzx7AUY9TyFnB6CZ7_%2B_uooPb7WHSpp7UE%3DYmKg%40mail.gmail.com
[3] - https://www.postgresql.org/message-id/CAA4eK1%2B1DMkCip9SB3B0_u0Q6fGf-D3vgqQodkLfur0qkL482g%40mail.gmail.com


-- 
With Regards,
Amit Kapila.

Commits

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

  1. Doc: Explain about Column List feature.

  2. Doc: fix column list vs. replica identity rules.

  3. Prohibit combining publications with different column lists.

  4. Fix the check to limit sync workers.

  5. Wait for subscription to sync in t/031_column_list.sql

  6. Move prattrs to the pg_publication_rel section in docs

  7. Allow specifying column lists for logical replication

  8. Fix row filters with multiple publications

  9. Fix publish_as_relid with multiple publications

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

  11. Add index on pg_publication_rel.prpubid

  12. Avoid using DefElemAction in AlterPublicationStmt

  13. Small cleanups related to PUBLICATION framework code

  14. Add PublicationTable and PublicationRelInfo structs

  15. Fix various concurrency issues in logical replication worker launching