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Universal Relation Assumption
The universal relation assumption in relational databases 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 relatio ... states, that one can place all data attributes into a (possibly very wide) table, which may then be decomposed into smaller tables as needed. However, the assumption that a single large table can capture real database designs is often plagued with a number of difficulties. The "nested universal relation" model has attempted to address some of the problems and offer improvements.Mark Levene, ''The nested universal relation database model,'' 2000. , pages 1-5. References External links Who won the Universal Relation wars?by Alberto Mendelzon Database theory {{Database-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relational Databases
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 rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igor Hawryszkiewycz
Igor Titus Hawryszkiewycz (born c. 1948) is an American computer scientist, organizational theorist, and Professor at the School of Systems, Management and Leadership of the University of Technology, Sydney, known for his work in the field of database systems, systems analysis, and knowledge management. Biography Hawryszkiewycz obtained his PhD in computer science from Massachusetts Institute of Technology in 1973"Igor Hawryszkiewycz, Professor and Head of School of Systems, Management and Leadership at University of Technology, Sydney." at linkedin.com. Accessed 2015-03-19. with the thesis, entitled "Semantics of data base systems." developed within the Project MAC. Hawryszkiewycz started his academic career as lecturer in information Systems at the University of Canberra The University of Canberra (UC) is a public research university with its main campus located in Bruce, Canberra, Australian Capital Territory. The campus is within walking distance of Westfield Belconne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
