Guide to Data Warehousing and Business Intelligence
There are many technical drivers in play that are motivating companies to establish data warehouses for online queries and analytics. These are summarized below.
Multiple Internal Databases
Most medium and large businesses operate dozens, if not hundreds of un-integrated application systems. Individual departments in companies often focus on their own narrow system and information needs and don’t see the corporate value of integrating data. When silos of un-integrated data exist, data soon gets out of synch. Companies have a need for database that reflects a "single version of truth". Data Warehouses can help do that.
“Out of the Box” purchased applications sometimes use underlying concepts and definitions that differ from those used by the business in existing custom built applications. For example, a “customer” in one system could encompass all current and past customers plus potential future customers. In another system, a customer might be defined more narrowly as someone who has purchased a product and service during the past 12 months. Such inconsistencies create problems from an analytical perspective. A count of customers done in the first database differ from a count done in the second. Companies have a need to align concepts and terminology. Data Warehouses help do this alignment.
Increasing Complexity of Systems
The underlying data structures of application systems are often very complicated. To create what would intuitively might appear to be a simple query often requires complex programming logic that involves navigating multiple database tables and or applications systems. Writing reports or queries can consequently take time and money. Companies have a need for a reporting environment that allows reports and queries to be generated quickly, inexpensively and without expensive IT skills. Data Warehouses can simplify the reporting environment.
Application System Evolution
Businesses are highly dynamic and applications systems are constantly needing to be enhanced to support new business requirements. When systems are changed, reports and queries that access any changed tables must also be updated. This maintenance work can be very costly. Businesses have a need to trim their application support costs. Data Warehouses can help shelter reports and queries from system changes that occur in "front end" operational systems.
Computer Networks and External Databases
The rapid growth of computer networks has allowed companies to exchange data with their suppliers, consumers, government bodies and other groups. Businesses often have a need to integrate data from internal and external databases. Data Warehouse can be designed to to integrate corporate data with external data for reporting purposes.