Oracle 11g and Oracle 10g Install together?

I have installed Oracle 10g and now want to insta开发者_运维知识库ll 11g also...How can I do it?.. I know that ORACLE_HOME environment variable need to be configured for each "oracle"..

Can you describe me steps how to do this?

Thank you very much in previous.

Thank you It helped me so much... The most important is that I should have chosen %ORACLE_HOME% like %ORACLE_BASE%...
Just %ORACLE_BASE% should be the same...And it works.

There's ususally not a lot of reasons why Oracle databases of different versions cannot run on the same machine, be it Windows or Linux/Unix. Reasons can be if you run Clustering software, which may not be of a lower version than any database version involved. Similar with Oracle Grid or Cloud. Other than that, I can't really think of reasons, but there may be excpetions, linked to specific OS. Usage of ORACLE_HOME's is how Oracle manages different databases and versions. The Oracle Homes should be different for each database, the Oracle Base should be the same, the central inventory must be shared, and the ownership (of Oracle Homes) may be shared or separated. Sharing Oracle Home is an option for advanced users only.