Re: Bug: Buffer cache is not scan resistant - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Bug: Buffer cache is not scan resistant
Date
Msg-id 21794.1173125927@sss.pgh.pa.us
Whole thread Raw
In response to Re: Bug: Buffer cache is not scan resistant  ("Simon Riggs" <simon@2ndquadrant.com>)
List pgsql-hackers
"Simon Riggs" <simon@2ndquadrant.com> writes:
> Best way is to prove it though. Seems like not too much work to have a
> private ring data structure when the hint is enabled. The extra
> bookeeping is easily going to be outweighed by the reduction in mem->L2
> cache fetches. I'll do it tomorrow, if no other volunteers.

[ shrug... ]  No one has yet proven to my satisfaction that L2 cache has
anything to do with this.  The notion that you can read a new disk page
into a shared buffer and have that buffer still be live in the processor
cache is so obviously bogus that I think there must be some other effect
at work.
        regards, tom lane


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