We are in the process of setting up a datawarehouse system with Oracle 9i as the database. We have 7 different sources of data and data from each source needs to be staged and then the star tables have to be leaded from the staging area.

I am new to Oracle. What is a good approach to use ?

Have different database instances created for each staging database or have one large database instance with many tablespaces created for each staging area ? It 'll be nice if you can highlight the advantages/disadvantages in using either of the approaches or if you can point me to some link that would help me.