Assume we have two relations R(A,B) and S(B,C). All three attributes (A, B, and C) are integer attributes. Assume that Relation R contains the following tuples: (1,2), (2,3), and (3,4). Assume that Relation S contains the following tuples (2,2), (2,3) and (5,1). Recall that a key is a minimal superkey, and that a key is not a superkey. (a) Give an example of an attribute (combination) that cannot be a key for relation S. (b) How many tuples are in the result of the cross-product between R and S? (c) How many tuples are in the result of the following relational algebra expression: T A(R natural Join

Assume we have two relations R(A,B) and S(B,C). All three attributes (A, B, and C) are integer attributes. Assume that Relation R contains the following tuples: (1,2), (2,3), and (3,4). Assume that Relation S contains the following tuples (2,2), (2,3) and (5,1). Recall that a key is a minimal superkey, and that a key is not a superkey. (a) Give an example of an attribute (combination) that cannot be a key for relation S. (b) How many tuples are in the result of the cross-product between R and S? (c) How many tuples are in the result of the following relational algebra expression: T A(R natural Join

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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