Alvaro Herrera wrote:
Heikki Linnakangas wrote:
What we could have is the semantics of "Return a buffer, with either
correct contents or completely zeroed out". It would act just like
ReadBuffer if the buffer was already in memory, and zero out the page
otherwise. That's a bit strange semantics to have, but is simple to
implement and works for the use-cases we've been talking about.
Huh, why does that work in the case where the recovery code reads a
page, then evicts it because of memory pressure, and later needs to read
it again?
I don't understand the problem. You only use ReadOrZeroBuffer when
you're going to replace the contents entirely, and don't care about the
old contents. If you want to read something in, you use ReadBuffer.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
---------------------------(end of broadcast)---------------------------
TIP 3: Have you checked our extensive FAQ?
http://www.postgresql.org/docs/faq
