Hi Murtuja, The odtug website also has a few very good articles available for free download at http://www.odtug.com/pls/htmldb/f?p=500:815:6729629124491114353:::815:P815_TOPIC:6 I would recommend Data Warehouse Architectures by George Lumpkin Database Design for Data Marts and Data Warehouses by Vincent Chazhoor Successful Dimensional Modeling of Very Large Data Warehouses by Bert Scalzo Optimizing Data Warehouse Ad-Hoc Queries Against "Star Schemas"by Bert Scalzo Advanced Dimensional Modeling by Vincent chazhoor
A few useful blogs in data warehouse area http://oraclesponge.wordpress.com http://pjsrandom.wordpress.com/ http://www.rittman.net/
Your Enterprise Oracle license should give you what you need. You are licensed for the partitioning features which are used a lot in data warehouses. In general, you need to start by understanding what the Star Schema is and why it is better for data marts than the conventional normalized schema. I would suggest you go to the site http://www.ralphkimball.com/ and begin reading. Ralph posts a lot of good articles online. But you may want to purchase one of Ralph's books because the book will present the information in a more organized manner. Once you understand the big picture of what data warehousing is and why sites implement it, for the DBA I would highly encourage you to look at Tim Gorman's paper Scaling to Infinity, which can be found at: http://www.tcoug.org/Archive/Fall2004/Fall2004.html. This will start you off in the right directions from the beginning.