RE: Disallow changing slot's failover option in transaction block

On Friday, April 19, 2024 10:54 AM Kuroda, Hayato/黒田 隼人 <kuroda(dot)hayato(at)fujitsu(dot)com> wrote:
> In your patch, the pg_dump.c was updated. IIUC the main reason was that
> pg_restore executes some queries as single transactions so that ALTER
> SUBSCRIPTION cannot be done, right?

Yes, and please see below for other reasons.

> Also, failover was synchronized only when we were in the upgrade mode, but
> your patch seems to remove the condition. Can you clarify the reason?

We used ALTER SUBSCRIPTION in upgrade mode because it was not allowed to use
connect=false and failover=true together when CREATE SUBSCRIPTION. But since we
don't have this restriction anymore(we don't alter slot when creating sub
anymore), we can directly specify failover in CREATE SUBSCRIPTION and do that
in non-upgrade mode as well.

Attach the V3 patch which also addressed Shveta[1] and Bertrand[2]'s comments.

[1] https://www.postgresql.org/message-id/CAJpy0uD3YOeDg-tTCUi3EZ8vznRDfDqO_k6LepJpXUV1Z_%3DgkA%40mail.gmail.com
[2] https://www.postgresql.org/message-id/ZiIxuaiINsuaWuDK%40ip-10-97-1-34.eu-west-3.compute.internal

Best Regards,
Hou zj