There are two alternative methods of representing an employee’s optional (single) phone number. The first is to use a nullable attribute and the second is to use a weak entity. 1. Given a requirement that a large number of the employees (> 80%) are assigned a phone number, which is the preferred method and why? 2. Given a requirement that only a small number of employees (< 10%) are assigned phone numbers, which is the preferred method and why? 3. How would the requirement of ‘multiple phone numbers can be assigned to an Employee’ affect your decision? Your answers should consider the performance tradeoff between number of database operations per query and record’s size.

There are two alternative methods of representing an employee’s optional (single) phone number. The first is to use a nullable attribute and the second is to use a weak entity. 1. Given a requirement that a large number of the employees (> 80%) are assigned a phone number, which is the preferred method and why? 2. Given a requirement that only a small number of employees (< 10%) are assigned phone numbers, which is the preferred method and why? 3. How would the requirement of ‘multiple phone numbers can be assigned to an Employee’ affect your decision? Your answers should consider the performance tradeoff between number of database operations per query and record’s size.

Oracle 12c: SQL

3rd Edition

ISBN:9781305251038

Author:Joan Casteel

Publisher:Joan Casteel

Chapter1: Overview Of Database Concepts

Section: Chapter Questions

Problem 5MC

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