What is Data Warehouse ?
The term "Data Warehouse" was first coined by Bill Inmon in 1990. He said that Data warehouse is subject Oriented, Integrated, Time-Variant and nonvolatile collection of data.This data helps in supporting decision making process by analyst in an organization
The operational database undergoes the per day transactions which causes the frequent changes to the data on daily basis.But if in future the business executive wants to analyse the previous feedback on any data such as product,supplier,or the consumer data. In this case the analyst will be having no data available to analyse because the previous data is updated due to transactions.
The Data Warehouses provide us generalized and consolidated data in multidimensional view. Along with generalize and consolidated view of data the Data Warehouses also provide us Online Analytical Processing (OLAP) tools. These tools help us in interactive and effective analysis of data in multidimensional space. This analysis results in data generalization and data mining.
The data mining functions like association,clustering ,classification, prediction can be integrated with OLAP operations to enhance interactive mining of knowledge at multiple level of abstraction. That's why data warehouse has now become important platform for data analysis and online analytical processing.