ETL-based data warehousing
The typical extract, transform, load (ETL)-based data warehouse uses staging, data integration, and access layers to house its key functions. The staging layer or staging database stores … See more

A data warehouse maintains a copy of information from the source transaction systems. This architectural complexity provides the opportunity to:
• Integrate data from multiple sources into a single database and data model. More congregation of … See more

The concept of data warehousing dates back to the late 1980s when IBM researchers Barry Devlin and Paul Murphy developed the "business data warehouse". In essence, the data warehousing concept was intended to provide an architectural model for the flow … See more

Bottom-up design
In the bottom-up approach, data marts are first created to provide reporting and analytical capabilities for specific business processes. These data marts can then be integrated to create a comprehensive data warehouse. The … See more

The environment for data warehouses and marts includes the following:
• Source systems that provide data to the warehouse or mart;
• Data … See more

A data mart is a simple form of a data warehouse that is focused on a single subject (or functional area), hence they draw data from a … See more

Facts
A fact is a value, or measurement, which represents a fact about the managed entity or system. See more