Database Concepts (8th Edition)
8th Edition
ISBN: 9780134601533
Author: David M. Kroenke, David J. Auer, Scott L. Vandenberg, Robert C. Yoder
Publisher: PEARSON
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Expert Solution & Answer
Chapter 2, Problem 2.26RQ
Explanation of Solution
Meaning of the Equation:
The given expression is,
(D, E)->F
Explanation:
The meaning of the following equation is:
- Given the value for both D and E simultaneously, represented as composite (D, E), user can determine the value of F.
- If one of the values of D or E is not given, user cannot determine the value of F.
- The Composite (D, E) is the determinant of F.
- F is functionally dependent on the composite (D, E).
- It is a composite key.
Example:
- For a table Employee containing attributes ‘employee_id’, ‘employee_name’ and ‘employee_department’, it is observed that user can fill an online form asking to enter the ‘employee_name’ and ‘employee_department’ simultaneously and the
Database Management System (DBMS) searches the employee database and retrieves the information about employee id .
Therefore, expression can be (employee_name, employee_department) -> (employee-id)...
Expert Solution & Answer
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Explain the meaning of the following expression: (D, E) → F Given this expression, tell if it is also true that: D → F and: E → F
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Chapter 2 Solutions
Database Concepts (8th Edition)
Ch. 2 - Prob. 2.1RQCh. 2 - Define the term entity, and give an example of an...Ch. 2 - Prob. 2.3RQCh. 2 - Prob. 2.4RQCh. 2 - Prob. 2.5RQCh. 2 - Prob. 2.6RQCh. 2 - Prob. 2.7RQCh. 2 - Prob. 2.8RQCh. 2 - Prob. 2.9RQCh. 2 - Define the term unique key and give an example.
Ch. 2 - Prob. 2.11RQCh. 2 - Prob. 2.12RQCh. 2 - Define the terms candidate key and primary key....Ch. 2 - Describe four uses of a primary key.Ch. 2 - Prob. 2.15RQCh. 2 - Prob. 2.16RQCh. 2 - Prob. 2.17RQCh. 2 - Explain the term foreign key, and give an example.Ch. 2 - Prob. 2.19RQCh. 2 - Prob. 2.20RQCh. 2 - Explain three possible interpretations of a null...Ch. 2 - Give an example of a null value (other than one...Ch. 2 - Prob. 2.23RQCh. 2 - Prob. 2.24RQCh. 2 - Prob. 2.25RQCh. 2 - Prob. 2.26RQCh. 2 - Prob. 2.27RQCh. 2 - Define the term primary key in terms of functional...Ch. 2 - Prob. 2.31RQCh. 2 - Examine the data in the Veterinary Office...Ch. 2 - Prob. 2.33RQCh. 2 - Describe a modification problem that occurs when...Ch. 2 - Prob. 2.35RQCh. 2 - Prob. 2.36RQCh. 2 - Prob. 2.37RQCh. 2 - Apply the normalization process to the Veterinary...Ch. 2 - Prob. 2.39ECh. 2 - Apply the normalization process to the Veterinary...
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