ocr: The Relational Model The relational model was developed by Codd in 1970 and subsequently refined by many others, particularly C.J.Date. The Phase3 database is a true relational database (as opposed to a database with some "relational" features), that is, it is relationally complete according to the relational definition. The main characteristics of arelationally complete database are : Data accessed by name only. No physical references (such as record numbers, file names, index names etc) are used to access the data in the database. Use of set algebra to manipulate tables. Data access is achie ...
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