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

From Florian Weimer
Subject Re: Bug: Buffer cache is not scan resistant
Date
Msg-id 82fy8k59nx.fsf@mid.bfk.de
Whole thread Raw
In response to Re: Bug: Buffer cache is not scan resistant  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
* Tom Lane:

> That makes absolutely zero sense.  The data coming from the disk was
> certainly not in processor cache to start with, and I hope you're not
> suggesting that it matters whether the *target* page of a memcpy was
> already in processor cache.  If the latter, it is not our bug to fix.

Uhm, if it's not in the cache, you typically need to evict some cache
lines to make room for the data, so I'd expect an indirect performance
hit.  I could be mistaken, though.

--
Florian Weimer                <fweimer@bfk.de>
BFK edv-consulting GmbH       http://www.bfk.de/
Kriegsstraße 100              tel: +49-721-96201-1
D-76133 Karlsruhe             fax: +49-721-96201-99


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