Horton

Re: Support logical replication of DDLs

Zheng Li <zhengli10@gmail.com>

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From: Zheng Li <zhengli10@gmail.com>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Peter Smith <smithpb2250@gmail.com>, Ajin Cherian <itsajin@gmail.com>, vignesh C <vignesh21@gmail.com>, li jie <ggysxcq@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>, Japin Li <japinli@hotmail.com>, rajesh singarapu <rajesh.rs0541@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-02-22T23:01:19Z
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.

Attachments

> > From the user perspective, I expect that the replicated objects are
> > created on the subscriber by the same owner as the publisher, by
> > default.
>
> OK, I agree. I think the use cases for matching the owner are likely
> more than the other way around. I can make the subscription option
> "match_ddl_owner" on by default in the next version.

> > > > Now, coming to implementation, won't it be better if we avoid sending
> > > > the owner to the subscriber unless it is changed for the replicated
> > > > command? Consider the current case of tables where we send schema only
> > > > if it is changed. This is not a direct mapping but it would be better
> > > > to avoid sending additional information and then process it on the
> > > > subscriber for each command.
> > >
> > > Right, we can do some optimization here: only send the owner for
> > > commands that create objects (CREATE TABLE/FUNCTION/INDEX etc.) Note
> > > that ALTER TABLE/OBJECT OWNER TO is replicated so we don't need to
> > > worry about owner change.
> >
> > What role will be used for executing ALTER and DROP commands on the
> > subscriber? the subscription owner?
>
> Yes, I think DROP and ALTER commands (and other non-CREATE commands)
> can be executed by the subscription owner (superuser).

Attached please find the new patch set with the following changes:
1. Changed the default value of the subscription option "match_ddl_owner" to on.
2. Changed deparser logic to only include the owner for commands that
create objects.
3. Addressed a merge conflict with a recent commit in pg_proc.dat.

Regards,
Zane