ISRO CS Quiz 8 : Database
Attempt now to get your rank among 755 students!
Question 1
Passenger (pid, pname, age)
Reservation (pid, cass, tid)
Table : Passenger
Table: Reservation
What pids are returned by the following SQL query for the above instance of the tables?
SELECT pid
FROM Reservation
WHERE class = 'AC' AND
EXISTS (SELECT *
FROM Passenger
WHERE age > 65 AND
Passenger . pid = Reservation.pid)
Question 2
Which of the following statements are TRUE about an SQL query?
P : An SQL query can contain a HAVING clause even if it does not have a GROUP BY clause
Q : An SQL query can contain a HAVING clause only if it has a GROUP BY clause
R : All attributes used in the GROUP BY clause must appear in the SELECT clause
S : Not all attributes used in the GROUP BY clause need to appear in the SELECT clause
Question 3
Consider the following schedule for transactions T1, T2 and T3: 
Which one of the schedules below is the correct serialization of the above?
Question 4
Which of the above schedules are conflict-serializable?
Question 5
Let r and s be two relations over the relation schemes R and S respectively, and let A be an attribute in R. then the Relational Algebra expression σA=a(r⋈s) is always equal to
Question 6
- 755 attempts
- 5 upvotes
- 40 comments
Tags :
GATE & PSU CSDatabases
