Обсуждение: Are extensions downgrade-safe?
Hi everyone
In PostgreSQL, there are times where a new version of an extension is included in a minor-version upgrade. If I do a minor-version upgrade of my PG database, upgrade the version of the extension and then have a need to revert (downgrade) to the old PG minor version, what should I do with the extension?
I searched the extensions in contrib and none comes with a downgrade script. Are extensions that do not come downgrade script downgrade-safe? Or do I need pg_dump or restore from backup to downgrade safely?
Thanks
Robert
Robert Pang <robertpang@google.com> writes:
> In PostgreSQL, there are times where a new version of an extension is
> included in a minor-version upgrade. If I do a minor-version upgrade of my
> PG database, upgrade the version of the extension and then have a need to
> revert (downgrade) to the old PG minor version, what should I do with the
> extension?
It'd really depend on what the particular extension upgrade script did.
A lot of the time you wouldn't have any issue, but there are probably
cases where reversing the effect of the upgrade script would be advisable.
We don't prepare downgrade scripts for the contrib modules; the question
comes up so seldom that it doesn't seem worth the maintenance effort.
But you could likely make one by studying the upgrade script and reversing
whatever it did.
regards, tom lane