Re: [PoC] pg_upgrade: allow to upgrade publisher node

On Tue, Sep 26, 2023 at 10:51 AM Hayato Kuroda (Fujitsu)
<kuroda.hayato@fujitsu.com> wrote:
>
> Again, thank you for reviewing! PSA a new version.

Thanks for the new patch. Here's a comment on v46:

1.
+Datum
+binary_upgrade_validate_wal_logical_end(PG_FUNCTION_ARGS
+{ oid => '8046', descr => 'for use by pg_upgrade',
+  proname => 'binary_upgrade_validate_wal_logical_end', proisstrict => 'f',
+  provolatile => 'v', proparallel => 'u', prorettype => 'bool',
+  proargtypes => 'pg_lsn',
+  prosrc => 'binary_upgrade_validate_wal_logical_end' },

I think this patch can avoid catalog changes by turning
binary_upgrade_validate_wal_logical_end a FRONTEND-only function
sitting in xlogreader.c after making InitXLogReaderState(),
ReadNextXLogRecord() FRONTEND-friendly (replace elog/ereport with
pg_fatal or such). With this change and back-porting of commit
e0b2eed0 to save logical slots at shutdown, the patch can help support
upgrading logical replication slots on PG versions < 17.

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com