Database System Concepts
Database System Concepts
7th Edition
ISBN: 9780078022159
Author: Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher: McGraw-Hill Education
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Chapter 7, Problem 11PE

Explanation of Solution

Primary key and foreign key constraint:

The given functional dependency (FD) which is used to decompose the given relational schema r into r1 and r2 is considered:

Considering the decomposed relation r1 and r2:

Explanation of Solution

Inconsistency that could arise:

When the foreign key constraint is not enforced on the relation r1 and r2 the following inconsistency may arise:

  • Consider a record is deleted from the relation r1; the referenced record that is obtained from the relation r2 will also be automatically deleted...

Explanation of Solution

Primary key and foreign key constraint:

Refer to the figure 7.19, which decomposes a relation into third normal form (3NF).

  • According to the above algorithm, make every α the primary key of a schema ri(αβ) that gets added to the schema according to the rule αβ

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