Re: Do we need so many hint bits?
От | Jeff Davis |
---|---|
Тема | Re: Do we need so many hint bits? |
Дата | |
Msg-id | 1353187807.10198.28.camel@jdavis-laptop обсуждение исходный текст |
Ответ на | Re: Do we need so many hint bits? (Andres Freund <andres@2ndquadrant.com>) |
Ответы |
Re: Do we need so many hint bits?
|
Список | pgsql-hackers |
On Sat, 2012-11-17 at 14:24 +0100, Andres Freund wrote: > I think the point is that to check whether the visibilitymap bit needs > to be unset What's the problem with that? If you already have the VM buffer pinned (which should be possible if we keep the VM buffer in a longer-lived structure), then doing the test is almost as cheap as checking PD_ALL_VISIBLE, because you don't need any locks. So, the proposal is: 1. Keep the VM buffer around in a longer-lived structure for scans and nodeModifyTable. 2. Replace all tests of PD_ALL_VISIBLE with tests directly against the VM, hopefully using a buffer that we already have a pin on. I haven't really dug into this yet, but I don't see any obvious problem. Regards,Jeff Davis
В списке pgsql-hackers по дате отправления: