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Principle Of Orthogonal Design
{{primary sources, date=March 2014 The principle of orthogonal design (abbreviated POOD) was developed by database researchers David McGoveran and Christopher J. Date in the early 1990s, and first published "A New Database Design Principle" in the July 1994 issue of Database Programming and Design and reprinted several times. It is the second of the two principles of database design, which seek to prevent databases from being too complicated or redundant, the first principle being the principle of full normalization ( POFN). Simply put, it says that no two relations in a relational database should be defined in such a way that they can represent the same facts. As with database normalization, POOD serves to eliminate uncontrolled storage redundancy and expressive ambiguity, especially useful for applying updates to virtual relations (e.g., view (database) In a database, a view is the result set of a ''stored'' query on the data, which the database users can query just as they woul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David McGoveran
David McGoveran (born 1952) is an American computer scientist and physicist, software industry analyst, and inventor. In computer science, he is recognized as one of the pioneers of relational database theory. Education David McGoveran majored in physics and mathematics, and minored in cognition and communication at the University of Chicago from 1973 to 1976, with graduate studies in physics and psycholinguistics. He pursued additional graduate studies from 1976 to 1979 at Stanford University. Career While a student he was employed by the Enrico Fermi Institute's Laboratory for Astrophysics and Space Research (Chicago 1973-4), Dow Chemical Company's Western Applied Science and Technology Laboratories (Walnut Creek, CA 1974), and University of Chicago Hospitals and Clinics (1975-6). After graduation from University of Chicago, he founded the consulting firm of Alternative Technologies(Menlo Park, CA 1976) under the mentoring of H. Dean Brown and Cuthbert Hurd. While sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christopher J
Christopher is the English version of a Europe-wide name derived from the Greek name Χριστόφορος (''Christophoros'' or '' Christoforos''). The constituent parts are Χριστός (''Christós''), "Christ" or "Anointed", and φέρειν (''phérein''), "to bear"; hence the "Christ-bearer". As a given name, 'Christopher' has been in use since the 10th century. In English, Christopher may be abbreviated as "Chris", "Topher", and sometimes " Kit". It was frequently the most popular male first name in the United Kingdom, having been in the top twenty in England and Wales from the 1940s until 1995, although it has since dropped out of the top 100. The name is most common in England and not so common in Wales, Scotland, or Ireland. People with the given name Antiquity and Middle Ages * Saint Christopher (died 251), saint venerated by Catholics and Orthodox Christians * Christopher (Domestic of the Schools) (fl. 870s), Byzantine general * Christopher Lekapenos (died 931) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database Design
Database design is the organization of data according to a database model. The designer determines what data must be stored and how the data elements interrelate. With this information, they can begin to fit the data to the database model.Teorey, T.J., Lightstone, S.S., et al., (2009). Database Design: Know it all.1st ed. Burlington, MA.: Morgan Kaufmann Publishers Database management system manages the data accordingly. Database design involves classifying data and identifying interrelationships. This theoretical representation of the data is called an ''ontology''. The ontology is the theory behind the database's design. Determining data to be stored In a majority of cases, a person who is doing the design of a database is a person with expertise in the area of database design, rather than expertise in the domain from which the data to be stored is drawn e.g. financial information, biological information etc. Therefore, the data to be stored in the database must be determined in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principle Of Full Normalization
A principle is a proposition or value that is a guide for behavior or evaluation. In law, it is a rule that has to be or usually is to be followed. It can be desirably followed, or it can be an inevitable consequence of something, such as the laws observed in nature or the way that a system is constructed. The principles of such a system are understood by its users as the essential characteristics of the system, or reflecting system's designed purpose, and the effective operation or use of which would be impossible if any one of the principles was to be ignored. A system may be explicitly based on and implemented from a document of principles as was done in IBM's 360/370 ''Principles of Operation''. Examples of principles are, entropy in a number of fields, least action in physics, those in descriptive comprehensive and fundamental law: doctrines or assumptions forming normative rules of conduct, separation of church and state in statecraft, the central dogma of molecular biology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relational Database
A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relational database systems are equipped with the option of using the SQL (Structured Query Language) for querying and maintaining the database. History The term "relational database" was first defined by E. F. Codd at IBM in 1970. Codd introduced the term in his research paper "A Relational Model of Data for Large Shared Data Banks". In this paper and later papers, he defined what he meant by "relational". One well-known definition of what constitutes a relational database system is composed of Codd's 12 rules. However, no commercial implementations of the relational model conform to all of Codd's rules, so the term has gradually come to describe a broader class of database systems, which at a minimum: # Present the data to the user as relati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database Normalization
Database normalization or database normalisation (see spelling differences) is the process of structuring a relational database in accordance with a series of so-called normal forms in order to reduce data redundancy and improve data integrity. It was first proposed by British computer scientist Edgar F. Codd as part of his relational model. Normalization entails organizing the columns (attributes) and tables (relations) of a database to ensure that their dependencies are properly enforced by database integrity constraints. It is accomplished by applying some formal rules either by a process of ''synthesis'' (creating a new database design) or ''decomposition'' (improving an existing database design). Objectives A basic objective of the first normal form defined by Codd in 1970 was to permit data to be queried and manipulated using a "universal data sub-language" grounded in first-order logic. An example of such a language is SQL, though it is one that Codd regarded as seriou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
View (database)
In a database, a view is the result set of a ''stored'' query on the data, which the database users can query just as they would in a persistent database collection object. This pre-established query command is kept in the database dictionary. Unlike ordinary ''base tables'' in a relational database, a view does not form part of the physical schema: as a result set, it is a virtual table computed or collated dynamically from data in the database when access to that view is requested. Changes applied to the data in a relevant ''underlying table'' are reflected in the data shown in subsequent invocations of the view. In some NoSQL databases, views are the only way to query data. Views can provide advantages over tables: * Views can represent a subset of the data contained in a table. Consequently, a view can limit the degree of exposure of the underlying tables to the outer world: a given user may have permission to query the view, while denied access to the rest of the base table. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
