22 Describe the purpose of the JOIN command in relational algebra The JOIN

22 describe the purpose of the join command in

This preview shows page 3 - 4 out of 4 pages.

22.Describe the purpose of the JOIN command in relational algebra. 23.Describe the purpose of the UNION command in relational algebra. 24.Are there any restrictions on the tables when using the UNION command? If so, what are these restrictions? 25.Describe the purpose of the INTERSECT command in relational algebra. 26.Describe the purpose of the SUBTRACT command in relational algebra. 27.Describe the purpose of the product process in relational algebra. 28.Describe the result of the division process in relational algebra.
Background image
29.In the TAL Distributors database shown in Figure 2-1, the Rep table contains four rows and the Customer table contains 12 rows. How many rows would be contained in the Cartesian product of these two tables?
Background image

You've reached the end of your free preview.

Want to read all 4 pages?

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture