From: Tom Lane <tgl@sss.pgh.pa.us>
To: Ants Aasma <ants@cybertec.at>
Cc: Atri Sharma <atri.jiit@gmail.com>
Cc: Amit Kapila <amit.kapila@huawei.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: Page replacement algorithm in buffer cache
Date: Fri, 22 Mar 2013 10:02:39 -0400
Message-ID: <3985.1363960959@sss.pgh.pa.us> (raw)
In-Reply-To: <CA+CSw_se74iDCLswBfF7_Rd1542nhyw-YSmQ+OqDwEzu0rZkSw@mail.gmail.com>
References: <CAOeZVic4HikhmzVD=ZP4JY9g8PgpyiQQOXOELWP=kR+=H1Frgg@mail.gmail.com>
<514bf302.84d5440a.43f2.ffffe411SMTPIN_ADDED_BROKEN@mx.google.com>
<08BBC126-D375-4743-B9A6-D1320D05D5C7@gmail.com>
<514c3395.487a420a.28d1.764eSMTPIN_ADDED_BROKEN@mx.google.com>
<CAOeZVifZ89tOtcKeC6C2917sVfSyR3xiMenorg8sNR2+y2W=Wg@mail.gmail.com>
<CA+CSw_se74iDCLswBfF7_Rd1542nhyw-YSmQ+OqDwEzu0rZkSw@mail.gmail.com>
List-Unsubscribe: <mailto:majordomo@postgresql.org?body=unsub%20pgsql-hackers>
Ants Aasma <ants@cybertec.at> writes:
> You might want to check out the LIRS cache replacement algorithm [1].
> That algorithm tries to estimate least frequently used instead of
> least recently used. Mysql uses it for their buffer replacement
> policy. There is also a clock sweep based approximation called
> CLOCK-Pro. Papers describing and evaluating both are available on the
> net. The evaluations in the papers showed significantly better
> performance for both of those compared to regular clock sweep or even
> ARC.
I seem to recall that CLOCK-Pro, or something named similarly to that,
was one of the alternatives discussed when we went over to the current
clock-sweep approach. And we definitely looked at ARC. It might be
worth checking the archives from back then to see what's already been
considered.
> However, I think the main issue isn't finding new algorithms that are
> better in some specific circumstances. The hard part is figuring out
> whether their performance is better in general.
Yeah. You can prove almost anything with the right set of test cases :-(
regards, tom lane
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-hackers@postgresql.org
Cc: tgl@sss.pgh.pa.us, ants@cybertec.at, atri.jiit@gmail.com, amit.kapila@huawei.com
Subject: Re: Page replacement algorithm in buffer cache
In-Reply-To: <3985.1363960959@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox