tailieunhanh - Lecture Database - Chapter 6: The relational algebra and relational calculus

Chapter 6 "The relational algebra and relational calculus" present contents: The relational algebra, unary relational operations, relational algebra operations from set theory, binary relational operations,. | Chapter 6 The Relational Algebra and Relational Calculus The relational algebra The basic set of operations for the relational model is the relational algebra. These operations enable a user to specify basic retrieval requests. The result of a retrieval is a new relation which may have been formed from one or more relations. The algebra operations produce new relations which can be further manipulated using operations of the same algebra. The relational algebra A sequence of relational algebra operations forms a relational algebra expression whose result will also be a relation that represents the result of a database .

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