Re: Oracle question from a Sys. admin, re: Solaris performance

From: Mark Bole <makbo_at_pacbell.net>
Date: Fri, 04 Mar 2005 00:41:42 GMT
Message-ID: <a9OVd.11105$Pz7.2931@newssvr13.news.prodigy.com>

Sybrand Bakker wrote:

> Comments embedded
>
>
> On 3 Mar 2005 12:55:11 -0800, tonij67_at_hotmail.com wrote:
>
>

[...]

>>
>>The article I looked at basically said that supporting 4 instances
>>would be a "nightmare" because you never know which instance is taking
>>resources.  I have a couple questions about this:
>>

[...]
>

>>- are we insane for having this many instances on a system?  I think
>>its the result of sale and marketing gone wild...
>>

>
>
> Insane is an understatement. The problem here an Oracle instance has a
> minimum amount of resources to operate at all. Say you need some 300M
> SGA at the least. And that times 50. You are now using 1.5 G of
> valuable RAM and you don't do yet anything, ie you have no users
[...]
>
> --
> Sybrand Bakker, Senior Oracle DBA

Actually, that calculation is 15 GB or RAM, not 1.5 GB.

To comment on the article you found, there can indeed be legitimate reasons for running two, three, or maybe even four instances on one server, especially if different versions of Oracle are involved or some instances have a different role, such as standby instead of primary or data warehouse instead of OLTP.

But fifty, especially if they are all running out of the same Oracle home, is either insane, or someone's idea of job security...

-Mark Bole Received on Thu Mar 03 2005 - 18:41:42 CST