In this paper, the authors describe a custom relational algebra query software environment that enables database instructors to teach relational algebra programming. Instead of defining query ...

(iii) Suppose the relation Likes contains all information about all customers. In other words, if the pair (cname,pizza) is not in the relation Likes, it means that the customer cname dislikes the ...

Abstract: Extensive work has recently been done on the evaluation of positive queries on probabilistic databases. The case of queries with negation has notoriously been left out, since it raises ...

To check your queries, you need to use your command line and change your current working directory to the respective folder. For example: change your working directory to solution_algebra for algebra ...

(1) The branch of mathematics that deals with relations; for example, AND, OR, NOT, IS and CONTAINS. (2) In a relational database, a collection of rules for dealing with tables; for example, JOIN, ...

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