

Introduction to Data Warehousing Concepts

A data warehouse is a database designed to enable business intelligence activities: it exists to help users understand and enhance their organization's performance. It is designed for query and analysis rather than for transaction processing, and usually contains historical data derived from transaction data, but can include data from other sources. Data warehouses separate analysis workload from transaction workload and enable an organization to consolidate data from several sources. This helps in:

  • Maintaining historical records

Why Data warehouses ?

Data warehouses are distinct from online transaction processing (OLTP) systems. With a data warehouse you separate analysis workload from transaction workload. Thus data warehouses are very much read-oriented systems. They have a far higher amount of data reading versus writing and updating. This enables far better analytical performance and avoids impacting your transaction systems. A data warehouse system can be optimized to consolidate data from many sources to achieve a key goal: it becomes your organization's "single source of truth". There is great value in having a consistent source of data that all users can look to; it prevents many disputes and enhances decision-making efficiency.

Who should learn Data warehouses ?


Scope of Data warehouses ?


Key Characteristics of a Data Warehouse

The key characteristics of a data warehouse are as follows:

  • Large amounts of historical data are used.
  • Both predefined and ad hoc queries are common.
  • The data load involves multiple sources and transformations.


Importent Question

  • What is data warehouse?
  • What is domain key normal form in DBMS?
  • What is linked server in SQL?
  • What is primary key in SQL?
  • What is the scope in Data Warehouse?