>Sorry, I used the french acronym.... SGBD is DBMS. ;-)

Ah! :)

>Obviously, both engines whould compete for the server's ressources, but this is a contengency plan, so as long as user can do a minimal level of work, it's fine and temporary.

Then you should not have a problem running both. What will the OS be on your server? Oracle 8i and 9i work fine under Win 2000 Server. I am not sure about Win 2003 Server as we have not tried that yet. Of course SQL Server is no problem on either OS.