Re: Column Filtering in Logical Replication

Tomas Vondra <tomas.vondra@enterprisedb.com>

From: Tomas Vondra <tomas.vondra@enterprisedb.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Justin Pryzby <pryzby@telsasoft.com>, Rahila Syed <rahilasyed90@gmail.com>, Peter Smith <smithpb2250@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, "shiy.fnst@fujitsu.com" <shiy.fnst@fujitsu.com>
Date: 2022-03-14T12:05:24Z
Lists: pgsql-hackers

On 3/14/22 10:53, Amit Kapila wrote:
> On Mon, Mar 14, 2022 at 2:37 AM Tomas Vondra
> <tomas.vondra@enterprisedb.com> wrote:
>>
>> On 3/12/22 05:30, Amit Kapila wrote:
>>>> ...
>>>
>>> Okay, please find attached. I have done basic testing of this, if we
>>> agree with this approach then this will require some more testing.
>>>
>>
>> Thanks, the proposed changes seem like a clear improvement, so I've
>> added them, with some minor tweaks (mostly to comments).
>>
> 
> One minor point: Did you intentionally remove
> list_free(rel_publications) before resetting the list from the second
> patch? The memory for rel_publications is allocated in
> TopTransactionContext, so a large transaction touching many relations
> will only free this at end of the transaction which may not be a big
> deal as we don't do this every time. We free this list a few lines
> down in successful case so this appears slightly odd to me but I am
> fine if you think it doesn't matter.

The removal was not intentional, but I don't think it's an issue exactly
because it's a tiny mount of memory and we'll release it at the end of
the transaction. Which should not take long.

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