# Database Management System MCQs

##### 11. Question

The order of an internal node in a B+ tree index is the maximum number of children it can have. Suppose that a child pointer takes 6 bytes, the search field value takes 14 bytes, and the block size is 512 bytes. What is the order of the internal node?

Answer

##### 12. Question

Consider the following relation schema pertaining to a students database:

Students (rollno, name, address)

Enroll(rollno,courseno, coursename)

Where the primary keys are shown underlined. The number of tuples in the student and Enroll tables are 120 and 8 respectively. What are the maximum and

minimum number of tuples that can be present in (Student * Enroll), where ‘*’ denotes natural join?

Answer

##### 13. Question

Relation R has eight attributes ABCDEFGH. Fields of R contain only atomic values.

F = {CH → G, A →BC, B →CFH, E →A, F →EG} is a set of functional dependencies (FDs) so that F+ is exactly the set of FDs that hold for R

How many candidate keys does the relation R have?

Answer

##### 14. Question

The relation scheme Student Performance (name, courseNo, rollNo, grade) has

the following functional dependencies:

name, courseNo, → grade

rollNo, courseNo → grade

name → rollNo

rollNo → name

The highest normal form of this relation scheme is

Answer

##### 15. Question

Suppose R1(A,B) and R2(C,D) are two relation schema. Let r1 and r2 be the corresponding relation instances. B is foreign key that refers to C in R2. If data in r1 and r2 satisfy referential integrity constraints, which of the following is ALWAYS TRUE?(GATE-2012)

Answer