Horton

Re: wake up logical workers after ALTER SUBSCRIPTION

Nathan Bossart <nathandbossart@gmail.com>

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From: Nathan Bossart <nathandbossart@gmail.com>
To: "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>
Cc: "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2022-11-22T04:39:16Z
Lists: pgsql-hackers

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On Tue, Nov 22, 2022 at 03:03:52AM +0000, Hayato Kuroda (Fujitsu) wrote:
> Just One comment: IIUC the statement "ALTER SUBSCRIPTION" can be executed
> inside the transaction. So if two subscriptions are altered in the same
> transaction, only one of them will awake. Is it expected behavior?
> 
> I think we can hold a suboid list and record oids when the subscription are
> altered, and then the backend process can consume all of list cells at the end of
> the transaction.

I think you are correct.  I did it this way in v2.  I've also moved the
bulk of the logic to logical/worker.c.

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.com

Commits

  1. Avoid type cheats for invalid dsa_handles and dshash_table_handles.

  2. Track logrep apply workers' last start times to avoid useless waits.

  3. Check for two_phase change at end of process_syncing_tables_for_apply.

  4. Wake up a subscription's replication worker processes after DDL.