Re: What MB/s is pulled from your buffer cache?

Rich Jesse schrieb:
> In our 11.2.0.3 production DB, I was looking at v$sysstat, and happened to
> order the view by VALUE DESC for kicks. The highest number is for the
> 'logical read bytes from cache' stat and is currently over 500TB. That
> seems abnormally large for less than 2 months of our ~800GB DB, so I thought
> I'd see what that boils down to in MB/s:
>
> It's over 100MB/s, which my knee jerk (emphasis on the latter) tells me that
> this seems abnormally high for our li'l DB.
>
> I'm curious to see how that number compares to other installations, if folks
> are willing.

This heavily depends on the quality of your execution plans - have a look at SQL "SQL ordered by Buffer Gets" in AWR/Statspack reports. I don't think that number to be abnormally high...

CACHE_READ_BYTES CACHE_READ_BYTES_TB STARTUP_TIME UPTIME_DAYS UPTIME_SECONDS BYTES_PER_SEC

---------------- ------------------- --------------------- -----------
-------------- -------------
         2.5E+16         23261681.06 16.12.2012 18:11:49         58.16
      5025448    4970112087

The DB is less than 2TB.

Regards
Martin

-- 
Usn's IT Blog for Linux, Oracle, Asterisk
http://www.usn-it.de

--
http://www.freelists.org/webpage/oracle-l