Re: Column Filtering in Logical Replication

Alvaro Herrera <alvherre@alvh.no-ip.org>

From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Tomas Vondra <tomas.vondra@enterprisedb.com>, Amit Kapila <amit.kapila16@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>, Rahila Syed <rahilasyed90@gmail.com>, Peter Smith <smithpb2250@gmail.com>, pgsql-hackers@postgresql.org
Date: 2022-01-03T15:01:59Z
Lists: pgsql-hackers
On 2022-Jan-03, Justin Pryzby wrote:

> Yes, I know both paths are hit now that it uses GetBool.
> 
> What I'm wondering is why tests didn't fail when one path wasn't hit - when it
> said am_partition=DatumGetChar(); if (!am_partition){}

Ah!

> I suppose it's because the am_partition=true case correctly handles
> nonpartitions.
> 
> Maybe the !am_partition case should be removed, and add a comment that
> pg_partition_tree(pg_partition_root(%u))) also handles non-partitions.
> Or maybe that's inefficient...

Hmm, that doesn't sound true.  Running the query manually, you get an
empty list if you use pg_partition_tree(pg_partition_root) with a
non-partition.  Maybe what was happening is that all columns were being
transmitted instead of only the required columns.  Maybe you're right
that the test isn't complete enough.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/



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