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Re: Multiple installed versions of Oracle

From: Terry Sutton <>
Date: Tue, 5 Apr 2005 10:55:21 -0700
Message-ID: <00f901c53a08$b82b1df0$16f5a8c0@TerrySutton>

Running multiple versions of Oracle on the same server is not really any different than running multiple instances on the same server. The issues the manager raises have little to do with the existence of multiple versions. They are related to having multiple instances. If a DBA administers the wrong DB, it doesn't matter if it was a different software version or the same version; they messed up because they didn't make sure their environment was set to the proper DB.

There is nothing technically negative about running multiple versions, as long as there is enough CPU and memory on the server to run the multiple instances involved. If your company is worried about DBAs not doing their job thoroughly, and wants to spend extra money, then putting each instance on a separate server can reduce risk. Of course the DBA can still login to the wrong server, instead of setting the wrong SID. And plenty of things can happen to DBs on separate servers (I've seen a production listener shutdown by someone working on a dev DB a couple times).


We are in the process of upgrading several databases from 8i on AIX 4.3.3 to 9 on AIX 5.2 or 10g on AIX 5.2. The target version depends upon whether or not the application is supported on 10g or not. If not will be migrating toward 9.
The manager of the unix area has indicated that he has seen issues at his previous shop with co-locating multiple versions of Oracle on the same server and is basically not allowing the practice. I have never seen or heard of this issue, but am trying to remain open-minded to his concern. Here are his statements verbatim:

Several occasions where server and db crashed due to dba administering db in an incorrect manner. IE mistook one version for the other. Applied the incorrect maintenance patch to the incorrect instance.

Several occasions where db versions did not play nice together 7.3.4 and 8i.

All occasions impacted SLA's and one instance required restore of db due to corrupt data.

I also contacted two DBA Manager friends and they are aware Oracle supports this strategy, however, both shops have standards in place that do not permit this practice - due primarily to the above incidents and to keep the environments simple / less complex. Does this make the planning of upgrades and maintenance a little more difficult - yes, but they both agreed that this best practice has solved many headaches and saved many hours of work.

Prior to his arrival we did have success running 7 and 8 on the same server. Frankly, I do not think the restriction is warranted. So what are your thoughts? And if you agree with me help me make a case for changing his mind. To complicate matters, he has more authority than me. Thanks

Tracy Rahmlow
The American Express Property Casualty companies 3500 Packerland Drive
DePere, Wisconsin 54115-9034
tel: 920-330-5164
fax: 920-330-5350
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-- Received on Tue Apr 05 2005 - 13:59:47 CDT

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