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Re: Column Filtering in Logical Replication

Tomas Vondra <tomas.vondra@enterprisedb.com>

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From: Tomas Vondra <tomas.vondra@enterprisedb.com>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Justin Pryzby <pryzby@telsasoft.com>, Amit Kapila <amit.kapila16@gmail.com>, "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>, Rahila Syed <rahilasyed90@gmail.com>, Peter Smith <smithpb2250@gmail.com>, pgsql-hackers@postgresql.org
Date: 2022-02-16T00:39:37Z
Lists: pgsql-hackers 

On 2/16/22 01:33, Alvaro Herrera wrote:
> On 2022-Feb-16, Tomas Vondra wrote:
> 
>> 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].
> 
> Thanks for doing this!
> 
>> 1) partitioning with pubviaroot=true
> 
> I agree that preventing the inconsistencies from happening is probably
> the best.
> 
>> 2) merging multiple column filters
>>
>> When the table has multiple column filters (in different publications), we
>> need to merge them. Which works, except that FOR ALL TABLES [IN SCHEMA]
>> needs to be handled as "has no column filter" (and replicates everything).
> 
> Agreed.
> 
>> 3) partitioning with pubivaroot=false
>>
>> When a partitioned table is added with (pubviaroot=false), it should not be
>> subject to column filter on the parent relation, which is the same behavior
>> used by the row filtering patch.
> 
> You mean each partition should define its own filter, or lack of filter?
> That sounds reasonable.
> 

If the partition is not published by the root, it shouldn't use the
filter defined on the root. I wonder what should happen to the filter
defined on the partition itself. I'd say

pubviaroot=false -> use filter defined on partition (if any)

pubviaroot=true -> use filter defined on root (if any)


I wonder what the row filter patch is doing - we should probably follow
the same logic, if only to keep the filtering stuff consistent.


regards

-- 
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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