Hi, On 2017-02-28 19:12:03 +0530, Pavan Deolasee wrote: > Since VM bits are only set during VACUUM which conflicts with CIC on the > relation lock, I don't see any risk of incorrectly skipping pages that the > second scan should have scanned.
I think that's true currently, but it'd also prevent us from doing that in additional places. Which, in my opinion, we really should (and I believe that's realistically achievable). Thus I really don't want to base the correctness of CIC - a relatively infrequent operation - on the assumption that no VM bits can be set concurrenty due to the SUE lock. Regards, Andres -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers