According to Data warehousing expert Bill Inmon, “A data warehouse is a subject oriented, integrated, time variant, non volatile collection of data in support of management’s decision making process”.
A data warehouse is a relational database that is the repository of an enterprise’s data which designed for improved query performance for large amount of data and analysing the data.
- Mainly used for queries, analysis and reporting rather than transactional activities.
- Usually stores historical data by extracting the information from transactional data and other sources.
- Data stored is subject oriented and time variant.
- Mostly non-volatile.
- Supports enterprise reporting, business intelligence and decision support.
Building the data warehouse involves significant effort towards the Data Warehouse Architecture and loading the data(ETL). Logical and Physical data modeling plays an important role in identifying the sources to storing that information.
A Data Warehouse environment includes an extraction, transportation, transformation, and loading (ETL) solution, an online analytical processing (OLAP) engine, client analysis tools, and other applications that manage the process of gathering data and delivering it to business users.
Business intelligence (BI) is a broad category of applications and technologies for gathering, storing, analyzing, and providing access to data to help enterprise users make better business decisions. BI applications include the activities of decision support systems, query and reporting, online analytical processing (OLAP), statistical analysis, forecasting, and data mining.
BI applications provide historical, current, and predictive views of business operations. Common functions of business intelligence applications are reporting, OLAP, analytics, data mining, business performance management, benchmarks, text mining, and predictive analytics.
Business intelligence often aims to support better business decision-making. Thus a BI system can be called a decision support system.
Business intelligence and Data warehousing:
Often BI applications use data gathered from a data warehouse or a data mart. However, not all data warehouses are used for business intelligence nor do all business intelligence applications require a data warehouse.