[jkatz05]

git diff REL_16_RC1..REL_16_0 doesn't show any changes that would require a pg_upgrade (at least from my read), so you should be able to upgrade without it.

[olavgg]

I just tested, I had to use pg_upgrade.

Error message: The database cluster was initialized with CATALOG_VERSION_NO 202306141, but the server was compiled with CATALOG_VERSION_NO 202307071.

[yobert]

You might just need to run:

    alter database mystuff refresh collation version;