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Tuesday, April 7, 2015
Relational model and Normalization Quiz 5
Relational model and Normalization Quiz
1. One or more columns of a composite primary (a primary key that comprises of more than one attribute) key can be allowed to have NULL values. TRUE / FALSE?
TRUE
FALSE
2. A foreign key of any table must refer to the primary key of its base table. TRUE/FALSE
TRUE
FALSE
3. The value of a foreign key attribute A of table R that refers to table S cannot be NULL if which of the following holds?
If attribute A is part of a primary key attribute in R
If attribute A refers the primary key of S
If attribute A is UNIQUE
If either a or b or both holds
4.
An attribute must contain only values consistent with the defined data format of that particular attribute
is called
Entity integrity
Referential integrity
User-defined integrity
Column integrity
5. The __________ property ensures that any instance of the original relation can be identified from corresponding instances of the smaller relations.
Lossless-join
Lossy-join
Both a and b
None of the above
6. In a functional dependency AB --> C, which of the following is true?
A is Determinant of C
B is Determinant of C
Both A and B together Determine C
All of the above
7. Which of the following is also called as
Subset dependencies
?
Entity integrity constraints
Referential integrity constraints
User-defined integrity constraints
Column integrity constraints
8. The determinant of a functional dependency refers to the attribute, or group of attributes, on the left-hand side of the arrow.
TRUE
FALSE
9. Assume a set of functional dependencies F = {Regno Name --> Gender, Regno --> Department, Regno --> Gender, Name --> Branch}. Here,
Regno Name --> Gender
is,
Gender is fully funcionally dependent on Regno and Name
Gender is partially funcionally dependent on Regno and Name
Name and branch together form the primary key
None of the above
10. _____________ ensure that a value that appears in one relation for a given set of attributes also appears for a certain set of attributes in another relation.
Referential integrity constraints
Weak entity sets
Entity integrity constraints
None of the above
Score =
Correct answers:
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