GATE PYQ

Database Management System

Q21.
Consider the entities 'hotel room', and 'person' with a many to many relationship 'lodging' as shown below:If we wish to store information about the rent payment to be made by person (s) occupying different hotel rooms, then this information should appear as an attribute of

Q22.
Consider the following ER diagram Which of the following is a correct attribute set for one of the tables for the minimum number of tables needed to represent M, N, P, R1, R2?

Q23.
Consider the following ER diagram The minimum number of tables needed to represent M, N, P, R1, R2 is

Q24.
Consider the following tables T1 and T2. In table T1, P is the primary key and Q is the foreign key referencing R in table T2 with ondelete cascade and on-update cascade. In table T2, R is the primary key and S is the foreign key referencing P in table T1 on-delete set NULL and on-update cascade. In order to delete record (3,8) from table T1, the number of additional records that need to be deleted from table T1 is _____.

Q25.
A locked database file can be

Q26.
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. The set of all tuples that must be additionally deleted to preserve referential integrity when the tuple (2,4) is deleted is:

Q27.
Let R(a, b, c) and S(d, e, f) be two relations in which d is the foreign key of S that refers to the primary key of R. Consider the following four operations R and S I. Insert into R II. Insert into S III. Delete from R IV. Delete from S Which of the following can cause violation of the referential integrity constraint above?

Q28.
Let R(a,b,c) and S(d,e,f) be two relations in which d is the foreign key of S that refers to the primary key of R. Consider the following four operations R and S I. Insert into R II. Insert into S III. Delete from R IV. Delete from S Which of the following can cause violation of the referential integrity constraint above?

Q29.
In a relational data model, which one of the following statements is TRUE?

Q30.
If every non-key attribute functionally dependent on the primary key, then the relation will be in