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Explain the data retrieval commands select and project as

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Explain the data retrieval commands select and project as used in relational algebra. Give examples of each
Submitted: 6 months ago.
Category: Homework
Expert:  HomeworkPete replied 6 months ago.
1. Select:The Select command is used to select tuples that satisfy the given predicate from a relation.It uses the notation σp(r), where σ stands for selection predicate and r stands for relation. p is prepositional logic formula which may use connectors like and, or, and not. An example is σsubject = "database"(Books) , which will select tuples from books where subject is 'database'.
Expert:  HomeworkPete replied 6 months ago.
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