A relational database contains two table student and department in which student table has columns roll_no, name and dept_id and department table has columns dept_id and detp_name. the following insert statements were executed successfully to populate the empty tables:

 Insert into department values (1, ‘Mathematics’)
 Insert into department values (2, ‘Physics’)
 Insert into student values (1, ‘Navin’,1)
 Insert into student values (2, ‘Mukesh’,2)
 Insert into student values (3, ‘Gita’,1)

How many rows and columns will be retrieved by the following SQL statement?

Select * from student, department;

The employee information in a company is stored in the relation

Employee (name, sex, salary, deptName)

Consider the following SQL query

  Select deptName
  From Employee
  Where sex = ‘M’
  Group by deptName
  Having avg(salary) >
  (Select avg (salary) From Employee);

It returns the names of the department in which

Consider the set of relations shown below and the SQL query that follows.

Students: (Roll_number, Name, Date_of_birth)
Courses: (Course number, Course_name, Instructor)
Grades: (Roll_number, Course_number, Grade)

Select distinct Name
From Students, Courses, Grades
Where Students.Roll_number = Grades.Roll_number
      and Courses.Instructor = 'Korth'
      and Courses.Course_number = Grades.Course_number
      and Grades.grade = 'A';

Which of the following sets is computed by the above query?

In SQL, relations can contain null values, and comparisons with null values are treated as unknown. Suppose all comparisons with a null value are treated as false. Which of the following pairs is not equivalent?