On Thu, Dec 11, 2008 at 7:15 PM, Heikki Linnakangas <[EMAIL PROTECTED]> wrote: > > > Yeah, if we accept that bits can be bogusly set. There is scenarios where > that can happen already, but they involve crashing, not during normal > operation and clean shut down. In the future, I'd like to move in the > direction of making the visibility map *more* reliable, not less, ultimately > allowing index-only-scans, so I'd rather not start relaxing that. >
Do we have any tests to prove that the VM page lock does not indeed become a bottleneck ? I can do some if we don't have already. > Only the first update to a page needs to clear the bit in the visibility > map, so I don't think it'll become a bottleneck in practice. Frequently > updated pages will never have the bit set in the visibility map to begin > with. > Well that's true only if you reject my heap-prune patch :-) Otherwise, heap-prune will again set the bit (and I believe that's the right thing to do) Thanks, Pavan -- Pavan Deolasee EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
