Re: Is my Oracle Server issuing more IO than it can handle

From: Niall Litchfield <>
Date: Tue, 7 Dec 2010 19:15:53 +0000
Message-ID: <>

Hi Harel,

I assume you intended to compare the working set of database changes to the cache size rather than the database size itself. The 2 things are not well related.

On 7 Dec 2010 19:12, "Harel Safra" <> wrote:

 This calculation is only true if you work with disk drive directly attached to you servers, and even then when there is no cache in the raid controller. Once you start working with central storage systems things like cache size, i/o distribution and disk sharing start to come into play.

For example, our EMC dMX4 storage has 96GB of cache. If your database is smaller than that (and nothing else uses the cache in this example) you could get very high throughput even with a single physical disk.

Do you know which kind of storage you use? Is you system the only system attached to it?

Harel Safra

On 07/12/2010 20:05, Oracle Dba Wannabe wrote:

> Do any of you have any thoughts w.r.t to question 1 - whether those
calculations can be represe...


> 1. Is there someway from awr that I can determine that the Oracle server
is issuing more IO than ...

Received on Tue Dec 07 2010 - 13:15:53 CST

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