November 2015
Beginner
464 pages
9h 46m
English
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Relational algebra
Relational algebra is the formal language of the relational model. It defines a set of closed operations over relations, that is, the result of each operation is a new relation. Relational algebra inherits many operators from set algebra. Relational algebra operations could be categorized into two groups:
- The first one is a group of operations which are inherited from set theory such as
UNION,INTERSECTION,SET DIFFERENCE, andCARTESIAN PRODUCT, also known asCROSS PRODUCT. - The second is a group of operations which are specific to the relational model such as
SELECTandPROJECT.
Relational algebra operations could also be classified as binary and unary operations. Primitive relational algebra operators have ultimate power of reconstructing ...
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