Monday, July 14, 2003		Feature

Store data first. Use it later
Ranjit Singh

THE basic idea behind the concept of warehousing is to store resources to use them later. The same concept has been adopted by the computer world.

Since the time automation became the keyword in most organisation, database started playing a major role. However, the sad part of the story is that in many organisations, despite the availability of powerful computers and high-speed networks, all officials of the organisation cannot access most of the data. This deficiency is termed as data in lock up. As the technology has been gaining height, the need of the collection of data at one place from several resources has emerged and has given rise to a new technology related to database technology called data warehousing a.k.a. single repository of data.

The data warehouse concept is different from the conventional DBMS software in the sense that information from different sources is integrated in advance and collected at one place for direct querying and analysis. A data warehouse is a relational database that is designed for query, analysis and for mining rather than transaction processing. It usually contains historical data that is derived from transaction data but can include data from other sources as well. It separates analysis workload from transaction workload and enables an organisation to consolidate data from several sources. This could be subject-oriented, integrated or non-volatile.

For example, you might want to learn more about your company’s sales data. To do this, you could build a warehouse concentrating on sales. This is subject oriented. The integrated form of data warehouse is closely related to subject orientation. Data warehouses need to have the data from disparate sources put into a consistent format.

Non-volatile means that data once entered into the warehouse should not change. This is logical because the purpose of a warehouse is to analyse what has occurred.