Hi,
> > Since commit bd8d9c9bdf "Widen MultiXactOffset to 64 bits",
> > "pg_multixact/members" should not be in that list anymore.
>
> I missed this one. Fixed, thanks.
>
> > Also, it seems misleading that a function called "check_*" doesn't
> > merely check for things, but renames files.
>
> Fair point. I renamed it to `ensure_long_slru_segment_filenames`.
>
> > Could we copy/link them with the new long names to begin with?
>
> That's an interesting idea.
>
> What I personally don't like about it is the fact that a single
> migration will affect the logic of every run of pg_upgrade, even in
> the far future, for instances that don't need this migration.
> Previously I showed [1] that the entire migration takes little time
> (note that we had to migrate pg_multixact/members back then). So I
> don't think this optimization is a good idea in the long run, unless
> we reach a consensus on the opposite.
Rebased.
--
Best regards,
Aleksander Alekseev
