Data Warehousing

According to Bill Inmon, "the Data Warehouse is a subject-oriented, integrated, time-variant, non-volatile collection of data used to support the strategic decision-making process for the enterprise. It is the central point of data integration for business intelligence and is the source of data for the data marts, delivering a common view of enterprise data."

Bill Inmon states these are the main types of data:
Subject-oriented: Data that gives information about a particular subject instead of about a company's on-going operations
Integrated: Data that is gathered into the data warehouse from a variety of sources and merged into a coherent whole
Time-variant: All data in the All data in the data warehouse is identified with a particular time period.
Non-volatile: Data is stable in a data warehouse. More data is added but data is never removed. This enables management to gain a consistent picture of the business.

In a nutshell, data warehousing is an architecture for managing all informational data within the data warehouse. This informational data can then be analyzed by online analytical processing (OLAP) tools which take a snapshot of the data warehouse and restructures it into organized data. There are three types OLAP - Multidimensional, Relational, and Hybrid.

FierceCIO covers data warehousing news and online analytical processing news in order to help CIOs and CTOs understand the changing business intelligence landscape.