INDEXING IN WAREHOUSE AND BUSINESS INTELLIGENCE

[arun a]

I have trouble to understand the indexing concept in both warehouse and BI "When does the intelligence go for indexing option !?" Is there any specific situation ?

[ngalemmo]

I do not fully understand the question.

If you are referring to indexing the physical database, then there really isn't any option... data warehouses are heavily indexed, much more extensivly than transactional systems. (Unless you are using specialized hardware, such as Netezza, which doesn't support indexing.) The need for indexes is primarily because a data warehouse is called on to service ad-hoc queries in an unstructured environment. How you index is a function of what database system you are using (Oracle, for example, has significantly different indexing methods than SQL Server, and Teradata is significantly different that the other two), and most vendors have a data warehousing section in their technical documentation that recommends suitable approaches for their system.