Degenerate Dimension in OBIEE

A degenerate dimension (DD) acts as a dimension key in the fact table, however does not join to a corresponding dimension table because all its interesting attributes have already been placed in other analytic dimensions.

Sometimes people want to refer to degenerate dimensions as textual acts, however they're not facts since the fact table's primary key often consists of the DD combined with one or more additional dimension foreign keys.
Degenerate dimensions commonly occur when the fact table's grain is a single transaction.


How to Implement in OBIEE :

Refer: http://obieetalk.com/oracle-bi-ee-101341-%E2%80%93-modeling-degenerate-dimensions-%E2%80%93-fact-attributes

Reference:http://www.kimballgroup.com/html/designtipsPDF/DesignTips2003/KimballDT46AnotherLook.pdf

Difference between Operational DB and DW

Operational DB	DW
It is designed to support operational monitoring	It is designed to support decision making process
Data is volatile	Data is Non-Volatile
Current Data	Historical Data
Detailed data	Summarized data
Normalization	De-Normalization
Designed for support ER- Modeling	Designed for support  Dimensional Modeling
Designed for running business	Design for Analyzing Business
Designed for clerical access	Designed for managerial access
More no of Joins	Few Joins
Few indexes	More indexes

Characteristics Features of Data.Warehouse

•      Time Variant

•      Non Volatile

•      Integrated DB

•      Subject Oriented DB

Time Variant

•      DW is a Time Variant db which supports the users in analyzing the business with different time periods

                                       

Non Volatile

•      DW is a Non Volatile DB

•      Once data entered into DW, it doesn’t reflects to the changes which takes place in Operational Source

Integrated DB

DW is an Integrated db which can store the data in an integrated and homogeneous format

System Oriented DB

•      DW is a System Oriented DB which supports the business needs of individual depts in the enterprise

E.g.  Sales, hr, Accounts, Loans etc 

What is a Data Warehouse

It is a database which is designed for analyzing business and decision making process

àIt contains required data in a required format according business analyst .