Re: Proposal: manipulating pg_control file from Perl

Aleksander Alekseev <aleksander@timescale.com> writes:
> Previously it was pointed out [1] that manipulating the pg_control
> file from Cluster.pm may be beneficial under certain conditions.

> As an example, one can downgrade the catalog version in pg_control,
> place input files for pg_upgrade, execute pg_upgrade and check the
> results. This would allow writing TAP-tests for pg_upgrade easily, in
> some cases at least. Perhaps there are other scenarios.

I'm finding it *really* hard to buy that as a credible use-case.
There is no situation where changing the catalog version in
pg_control, by itself, is a useful thing to do: you'd have to also
install matching catalog contents.  But then wherever you got the
catalog contents from would be a perfectly good source for a matching
pg_control, no?  Likewise, the idea that pg_control should be
architecture-independent when none of the catalogs or data files are
seems pretty pointless.

Maybe there's a case to be made for doing something here, but you
haven't made it.

            regards, tom lane