Horton

Re: Support logical replication of DDLs

Aleksander Alekseev <aleksander@timescale.com>

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From: Aleksander Alekseev <aleksander@timescale.com>
To: Zheng Li <zhengli10@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-02-24T08:56:36Z
Lists: pgsql-hackers

Commits

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

  1. Add a run_as_owner option to subscriptions.

  2. Refactor pgoutput_change().

  3. Print the correct aliases for DML target tables in ruleutils.

  4. Fix object identity string for transforms

  5. Add grantable MAINTAIN privilege and pg_maintain role.

  6. Get rid of recursion-marker values in enum AlterTableType

  7. Release cache tuple when no longer needed

  8. Empty search_path in logical replication apply worker and walsender.

  9. Refactor format_type APIs to be more modular

  10. Use wrappers of PG_DETOAST_DATUM_PACKED() more.

Hi Zheng,

> >Also, I suspect that implementing it may be a bit challenging. What if we
> >focus on table-level replication for now?
>
> I think it is due to the fact that the current limitations in logical
> replication are
> holding it back in major version upgrade (MVU). Online / reduced downtime MVU
> is a popular request from customers, and why we should enhance logical
> replication
> to support this use case.
>
> Also I think table-level DDL replication is actually more challenging,
> especially in
> the FOR TABLE case, due to the fact that differences are expected to
> occur between the
> source and target database. Marcos’ comment also justifies the complexity
> in this case. Whereas database-level DDL replication in the FOR ALL
> TABLE case is
> relatively simple because the source and target database are (almost) identical.

Sure, I don't insist on implementing table-level replication first.
It's up to you. My point was that it's not necessary to implement
everything at once.

-- 
Best regards,
Aleksander Alekseev