GATE 2023 Database Quiz 20

Consider the relation database, where primary keys are underlined
• Student (Student_name, street, city)
• Score (Student_name, Branch_name, marks)
• Branch (Branch_name, HOD)
• Manages (Student_name, Faculty_name)
What does the following tuple relational calculus query produce?

{S₁.student_name | S₁∈ Score¬∃ S₂∈ Score(S₁[marks]≤S₂marks∃e₂∈ student(S₂[student_Name])

=e₂[student_name]e₂[city] = ‘Mumbai’))

Consider the following tuple relational calculus:

{t | Ǝ s ε instructor (t[name] = s[name] ᴧ Ǝ u ε department (u[dept_name] = s[dept_name]

ᴧ u[building] = “Taylor”))}

What does the given expression perform?

Domain relational Calculus is a:

The relational algebra expression equivalent to the following tuple calculus relation:

Consider the following relational schema

The number of records resulted by below SQL query are _______ .

Select *

From R

Where C = ALL (select B

From R

Where A > 10);