Database Management System MCQs

1. Question

Consider a relation scheme R = (A,B,C,D,E,H) on which the following functional dependencies hold: {A  →B, BC  →D, E  →C, D  →A}. What are the candidate keys of R?




Answer
2. Question

The relation book (title,price) contains the titles and prices of different books. Assuming that no two books have the same price, what does the following SQL query list?
select title
from book as B
where (select count(*)
from book as T
where T.price>B.price)<5




Answer
3. Question

The following table has two attributes A and C where A is the primary key and C is the foreign key referencing a with on-delete cascade.

Untitled

The set of all tuples that must be additionally deleted to preserve referential integrity when the tuple (2,4) is deleted is:

 




Answer
4. Question

The protocol data unit (PDU) for the application layer in the Internet stack is




Answer
5. Question

Which one of the following statements about normal forms is FALSE?




Answer

Leave a Reply