Codd’s 12 Rules Relational Database Management Cheat Sheet by [deleted] via cheatography.com/2754/cs/15880/ Introdu​ ction Codd;'s 12 Rules Edgar F. Codd wrote a paper in 1985 defining rules for Relational Database Management Systems (RDBMS), which revolut​ ion​ ized the IT industry. In 1993, Codd and colleagues worked up these 12 rules for defining OLAP (Online Analytical Process​ ing), an industry of software and data processing which allows consoli​ dation and analysis of data in a multidi​ men​ sional space. Codd’s 12 rules are: Source: Codd E.F., Codd S.B., and Salley C.T. “Providing OLAP (On- line Analytical Process​ ing) to User-An​ aly​ sts: An IT Mandate”. Codd & Date, Inc 1993. <http://​ www​ .fp​ m.co​ m/​ ref​ er/​ cod​ d.html> 1. Multidi​ men​ sional conceptual view 6. Generic Dimensi​ ona​ lity User-an​ alysts would view an enterprise as being multidi​ men​ sional in nature – for example, profits could be viewed by region, product, Every data dimension should be equivalent in its structure and ​ ​ time period, or scenario (such as actual, budget, or forecast). Multi-‐​ operational capabilities. dime​ nsi​ onal data models enable more straigh​ tfo​ rward and intuitive manipul​ ation of data by users, including “slicing and dicing“. 7. Dynamic sparse matrix handling The OLAP server’s physical structure should have optimal sparse 2. Transpa​ rency matrix handling. When OLAP forms part of the users’ customary spreads​ heet or graphics package, this should be transpa​ rent to the user. OLAP 8. Multi-user support should be part of an open systems archite​ cture which can be OLAP tools must provide concurrent retrieval and update access, embedded in any place desired by the user without adversely integrity and security. affecting the functio​ nality of the host tool. The user should not be exposed to the source of the data supplied to the OLAP tool, which 9. Unrestr​ icted cross-d​ ime​ nsi​ onal operations may be homogen​ eous or heterog​ ene​ ous. Computa​ tional facilities must allow calcula​ tion and data manipul​ ation across any number of data dimensi​ ons, and must not restrict any 3. Accessi​ bility relatio​ nship between data cells. The OLAP tool should be capable of applying its own logical structure to access heterog​ eneous sources of data and perform any 10. Intuitive data manipul​ ation convers​ ions necessary to present a coherent view to the user. The Data manipul​ ation inherent in the consoli​ dation path, such as drilling tool (and not the user) should be concerned with where the physical down or zooming out, should be accompl​ ished via direct action on data comes from. the analytical model’s cells, and not require use of a menu or multiple trips across the user interface. 4 Consistent reporting perform​ ance Perform​ ance of the OLAP tool should not suffer signifi​ cantly as the 11. Flexible reporting number of dimensions is increased. Reporting facilities should present informa​ tion in any way the user wants to view it. 5. Client/​ server archite​ cture The server component of OLAP tools should be suffici​ ently intelli​ gent 12. Unlimited Dimensions and aggrega​ tion levels that the various clients can be attached with minimum effort. The The number of data dimensions supported should, to all intents and server should be capable of mapping and consoli​ dating data purposes, be unlimited. Each generic dimensions should enable an between disparate databases. essenti​ ally unlimited number of user-de​ fined aggrega​ tion levels within any given consoli​ dation path. By [deleted] Published 31st May, 2018. Sponsored by CrosswordCheats.com cheatography.com/deleted- Last updated 31st May, 2018. Learn to solve cryptic crosswords! 2754/ Page 1 of 1. http://crosswordcheats.com.