> Tom wants to ditch (2) to allow the others. Robert wants to ditch
> (1) to allow the others. I want to ditch (3) to allow the others.
> Andres wants (3) and has not expressed an opinion on which he would
> prefer to give up to get it. I believe Josh Berkus has mentioned
> how useful he thinks both (1) and (2) would be, without really
> commenting on (3).
As I understand it, we don't currently have any mechanism in Postgres
which would cause allocated-but-empty pages. That we *might* have such
a thing in 9.4 doesn't seem like a sufficient obstacle; we also might not.
Further, I don't think that pg_upgrade is really a red card here.
Matviews will be a new feature for 9.3. If we end up having to say "if
you use pg_upgrade to upgrade to 9.4, you will need to rebuild your
matviews afterwards", then that's what happens. People are used to some
wonkiness in new features, and at this point the majority of our users
don't use pg_upgrade.
So, yes, I'd vote for (1) and (2) over (3), if that's the options which
make sense.
--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com