online analytical processing

n. (OLAP, abbr.)Techniques using decision support software that allow a user to analyze information that has been summarized into multidimensional views and hierarchies.


OLAP 1994 E. F. Codd, father of the relational database, and his associates have produced a white paper listing the 12 rules for OLAP (on-line analytical processing) systems. The list is fundamentally a formula for a successful information system, whether you call it an EIS, a DSS, or a business information system. ¶ 1. Multidimensional conceptual view. This supports EIS 'slice-and-dice' operations and is usually required in financial modeling. – 2. Transparency. OLAP systems should be part of an open system that supports heterogeneous data sources. Furthermore, the end user should not have to be concerned about the details of data access or conversions. – 3. Accessibility. The OLAP should present the user with a single logical schema of the data. – 4. Consistent reporting performance. Performance should not degrade as the number of dimensions in the model increases. – 5. Client/server architecture. Requirement for open, modular systems. – 6. Generic dimensionality. Not limited to 3-D and not biased toward any particular dimension. A function applied to one dimension should also be able to be applied to another. – 7. Dynamic sparse-matrix handling. Related both to the idea of nulls in relational databases and to the notion of compressing large files, a sparse matrix is one in which not every cell contains data. OLAP systems should accommodate varying storage and data-handling options. – 8. Multiuser support. OLAP systems, like EISes, need to support multiple concurrent users, including their individual views or slices of a common database. – 9. Unrestricted cross-dimensional operations. Similar to rule 6; all dimensions are created equal, and operations across data dimensions do not restrict relationships between cells. – 10. Intuitive data manipulation. Ideally, users shouldn't have to use menus or perform complex multiple-step operations when an intuitive drag-and-drop action will do. – 11. Flexible reporting. Save a tree. Users should be able to print just what they need, and any changes to the underlying financial model should be automatically reflected in reports. – 12. Unlimited dimensional and aggregation levels. A serious tool should support at least 15, and preferably 20, dimensions.