I am totally new about OLAP and data warehousing. Our company uses traditional reporting, but we also consider that we may use OLAP in the future. I have read some about OLAP, but I am confused about the process. In the star schema xml, there are fact and dimension tables associated with. Do I create the fact and dimension tables manually and use ETL tool to load the data over, before I write and verify the star schema?
You need to enable the OLAP option of the database, if it is not already enabled, and then define some dimensions and cubes on top of your star schema using AWM (Analytic Workspace Manager). There are tutorials and demonstrations on the OLAP OTN page. http://www.oracle.com/technetwork/database/options/olap/index.html