Horton

Re: EXPLAIN ANALYZE printing logical and hardware I/O per-node

Trevor Talbot <quension@gmail.com>

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From: "Trevor Talbot" <quension@gmail.com>
To: Decibel! <decibel@decibel.org>
Cc: "Neil Conway" <neilc@samurai.com>, "Gregory Stark" <stark@enterprisedb.com>, "pgsql-hackers list" <pgsql-hackers@postgresql.org>
Date: 2007-12-18T06:29:54Z
Lists: pgsql-hackers 
On 12/17/07, Decibel! <decibel@decibel.org> wrote:

> Also, has anyone looked into adding a class of system calls that
> would actually tell us if the kernel issued physical IO? I find it
> hard to believe that other RDBMSes wouldn't like to have that info...

Non-blocking style interfaces can help here. On Windows, for instance,
a read returns data at the call site if it was satisfied by cache,
instead of invoking the asynchronous notification.