• Question 18 All primary key entries are unique, and no part of a primary key may be ____.
• Question 19 ____ yields only the rows that appear in both tables.
• Question 20 ____ combines all rows from two tables, excluding duplicate rows.
• Question 21 The ____ relationship should be rare in any relational database design.
• Question 22 A( n) ____ join only returns matched records from the tables that are being joined.
• Question 23 In an outer join, the matched pairs would be retained and any unmatched values in the other table would be left ____.
• Question 24 A( n) ____ is perceived as a two-dimensional structure composed of rows and columns.
• Question 25 A ____ should be a derived attribute.
• Question 26 A relationship is an association between ____.
• Question 27 Ideally, an entity identifier is composed of ____ attribute( s).
• Question 28 An entity is said to be ____-dependent if it can exist in the database only when it is associated with another related entity occurrence.
• Question 29 A derived attribute ____.
• Question 30 The M: N relationship between STUDENT and CLASS must be divided into two 1: M relationships through the use of the ENROLL entity; the ENROLL entity is ____.
• Question 31 Knowing the ____ number of entity occurrences is very helpful at the application software level.