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The Data Warehouse. from William H. Inmon, Building the Data Warehouse (4 th ed). Data Warehouse =. architecture (not a technology) example of Decision Support System. Data Placement. DSS - Decision Support Systems (analytical function) OLTP – Online Transactional Processing
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The Data Warehouse from William H. Inmon, Building the Data Warehouse (4th ed)
Data Warehouse = architecture (not a technology) example of Decision Support System
Data Placement • DSS - Decision Support Systems (analytical function) • OLTP – Online Transactional Processing (operational function) • Archival data – cheaper/slower storage
primitive data operational day-to-day clerical function non-redundant non-integrated run repetitively derived data analytical historical managerial function redundant data integrated run heuristically OLTP DSS
A Definition: “A data warehouse is a subject-oriented, integrated, non-volatile, and time-variant collection of data in support of management’s decisions.” (a sophisticated series of snapshots…)
Design Decisions • Granularity - level of detail or summarization of the units of data in the data warehouse (more detail = lower level of granularity) • Partitioning – breakup of data into separate physical units that can be handled independently
Major Components • Design of Data Warehouse itself • Interface from operational systems -role of extract (ETL) software [Extract/Transform/Load] -element of time (compound keys) -data purging
Indirect Use of Data Warehouse Data An analysis program periodically spins off a file to the operational environment that includes specific summarized data Airline commission example Retail personalization example Credit scoring example
Data Warehouse Requirements • Manage large amounts of data • Manage data on diverse media • Easily index and monitor • Interface with varying technologies • Store and access data in parallel • Metadata control (by “user”) • Contextual information (vs content) • Efficiently use indexes • Support compound keys