On Tue, Apr 30, 2013 at 10:19 PM, Kevin Grittner <kgrittn@ymail.com> wrote:
> Clearly we would need to change how we do recovery of unlogged
> relations to both allow unlogged matviews and keep the populated
> state in pg_class. I don't think we can really make the "two
> places" technique work, where the recovery state of the unlogged
> matview is used to trigger a pg_class change. For one thing, it
> was really messy -- far more so than current code. For another
> thing, the matview would show as good until it was first opened,
> which was nasty.
Can I ask what is the design goal of unlogged relations? Are they just
an optimization so you can load lots of data without generating piles
of wal log? Or are they intended to generate zero wal traffic so they
can be populated on a standby for example, or outside a transaction
entirely?
Because if it's the former then I don't see any problem generating wal
traffic to update the pg_class entry. If they can satisfy the latter
that gets a bit trickier.
--
greg