Re: SQL ordered by Physical Reads (UnOptimized)

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Sat, 21 May 2011 21:59:03 +0100
Message-ID: <EBFA6679ECAB49D9882627222CF1CF7E_at_Primary>


  • Original Message ----- From: "Tanel Poder" <tanel_at_tanelpoder.com> To: <karlarao_at_gmail.com> Cc: <kylelf_at_gmail.com>; "ORACLE-L" <Oracle-L_at_freelists.org> Sent: Saturday, May 21, 2011 3:25 PM Subject: Re: SQL ordered by Physical Reads (UnOptimized)

> These slides fail to mention that the optimized reads statistic is also
> incremented when smart scans can "optimize IO" by avoiding doing it thanks
> to storage indexes. So, if your OLTP database has some smart scanning
> happening in it (usually thanks to various reports, etc) then the optimized
> reads may be either due to flash cache hits or storage index IO elimination.
>
> --
> Tanel Poder
> http://blog.tanelpoder.com
>

And why is my laptop reporting optimized reads ?

Regards

Jonathan Lewis
http://jonathanlewis.wordpress.com

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Received on Sat May 21 2011 - 15:59:03 CDT

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