On Sun, Nov 5, 2017 at 2:22 PM, Oleg Bartunov <obartu...@gmail.com> wrote: >> IIRC there were some concerns about what happened with pg_upgrade, >> with consuming precious toast bits, and a few other things. > > yes, pg_upgrade may be a problem.
A basic problem here is that, as proposed, DROP COMPRESSION METHOD may break your database irretrievably. If there's no data compressed using the compression method you dropped, everything is cool - otherwise everything is broken and there's no way to recover. The only obvious alternative is to disallow DROP altogether (or make it not really DROP). Both of those alternatives sound fairly unpleasant to me, but I'm not exactly sure what to recommend in terms of how to make it better. Ideally anything we expose as an SQL command should have a DROP command that undoes whatever CREATE did and leaves the database in an intact state, but that seems hard to achieve in this case. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers