Re: How to create a second instance?

markus<markus.grau_at_myrealbox.com> wrote in message news:<a0f3mf$2vmu$1_at_koroth.muc.eurocyber.net>...
> Hi @all,
>
> im not very familiar with Oracle and have the following problem:
>
> We have an Oracle 8.1.6 Enterprise Server on RedHat Linux 6.1
> On instance is up and running.
>
> I want to create another one for a new project, which has its own DB-Files/Control-Files/User and so on.
>
> But how do I create this other instance? Which environment variables should I set?
>
> Thankxx
> markus

In general on unix systems, you want to change the environment variable ORACLE_SID to the new instance name, and copy over the $ORACLE_HOME/dbs/*$ORACLE_SID.ora (with the old ORACLE_SID) to $ORACLE_HOME/dbs/*$ORACLE_SID.ora (with the new one). Watch out for links, on many systems $ORACLE_HOME/dbs/config$ORACLE_SID.ora is actually a link to elsewhere. Modify those files to reflect the new ORACLE_SID (if you are using OFA rules, there likely will be directory names with ORACLE_SID in it), being especially careful to get the control files names different than the old ones!

To actually create the instance, you can either use a tool for creating instances, copy and rename the old instance (search for other posts on how to do that), or use the create database statement, preferably in a script. If you have access to metalink.oracle.com, there are scripts for creating create database statements from existing databases, which you can edit for the new one.

Be aware that in many cases, one wants to use the same instance but different schemata for different projects. There are a number of arguments as to whether to use one or many instances, the major ones are limitations in SGA size/performance tuning (all SGA should be no more than 40-60% of real mem), versus backup procedures (some projects may have different uptime/recovery requirements), and user definition requirements such as public synonyms or how many user logins there will be.

jg

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And watch out for directories named ...!