The 12 Rules of OLAP
Dr. E. F. Codd, father of the relational database and his .associates have produced a white paper (for more information on the white paper, call Arbor Software, Santa Clara, CA) listing the 12 rules for OLPA 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. The rules are given below:
1. Multidimensional conceptual views - 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. Further more, the end user should not have to be concerned about the details of data access or conversions.
3. Accessibility - The ALAP should present the user with a single logical schema of the data.
4. Consistent reporting performance - Performance should degrade as the number of dimensions in the model increases.
5. Client/server architeGtClfe - Requirement for open, modular systems.
6. Generic dimensionality - Not limited to 3 D and biased towards any particular dimension. 'A function applied to one dimension should also be able to be applied to another.
7. Dynamic sparse-marti)( handling - Related both to the idea of nulls in relational databases and not to the notion of compressing large files, a sparse martix is one in which not every cell contains data. OLAP systems should accommodate varying storage and data-handling options.
8. Multi-user 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 ang 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 muWple-step operations when an intuitive drag-and-drop action will do.
11. Flexible reporting - sa:ve 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 dimensionqJ. and aggregation levels - A serious tool should support at least T5 an referably 20 dimensions