DBI202 (Full)-Final Exam with Guaranteed Pass Solutions Updated.

DBI202 (Full)-Final Exam with
Guaranteed Pass Solutions 2026-2027
Updated.
a - Answer QN=1 (6803) A ____ is a logically coherent collection of data with some inherent
meaning, representing some aspect of real world and being designed, built and populated with
data for a specific purpose

a. Database

b. Database Instance

c. Schema

d. Schema Instance



b - Answer QN=2 (6801) Choose the most correct statement.

a. Database is created and maintained by a DMBS

b. All of the others

c. Database is a collection of data that is managed by a DBMS

d. Database is a collection of information that exists over a long period of time



b - Answer QN=3 (6802) Which of following is never used as a data model?

a. Hierarchical data model

b. None of the others

c. Graph-based data model

d. Tree-based data model

e. Relational data model



a - Answer QN=4 (6817) A ____ is a relation name, together with the attributes of that
relation.

a. schema

b. database

c. database instance

d. schema instance



a - Answer QN=5 (6824) A ___ is a notation for describing the structure of the data in a
database, along with the constraints on that data

a. data model

b. database management system

,c. data operation

d. data manipulation



a - Answer QN=6 (6827) A _____ is a language for defining data structures

a. DDL

b. DML

c. DCL

d. None of the others



a - Answer QN=7 (6834) Which statement is used to remove a relation named R?

a. DROP TABLE R;

b. REMOVE TABLE R;

c. DELETE TABLE R;

d. TRUNCATE TABLE R;



b - Answer QN=8 (6829) What is another term for a row in a relational table?

a. Attribute

b. Tuple

c. Field

d. Relation



d

A constraint of any kind on a relation is said to be *trivial* if it holds for every instance of the
relation, regardless of what other constraints are assumed. - Answer QN=9 (7961) Given a
relation R(A,B,C,D). Which of the followings is trivial?

a. A->AB

b. A->->AB

c. A->BCD

d. A->->BCD



b

Từ A -> B và D, từ C -> B. Suy ra bộ AC là key - Answer QN=10 (7972) Let R(ABCD) be a relation
with functional dependencies

{A -> B,

C -> B,

B -> D}

,What is the key for R (choose one)

a. AB

b. AC

c. AD

d. BD



a

A *superkey* is a set of attributes that can uniquely identify a tuple in a relation. Since the only
key of R is {A1, A2}, it means that this combination of attributes can uniquely identify a tuple in
the relation. However, any superset of this key is also considered a superkey. So the possible
superkeys for R are: {A1,A2}, {A1,A2,A3}, {A1,A2,A4} and {A1,A2,A3,A4}. Therefore, R has 4
superkeys. - Answer QN=11 (7966) Suppose R is a relation with attributes A1, A2, A3, A4.

The only key of R is {A1, A2}. So, how many super-keys do R have?

a. 4

b. 8

c. 12

d. 16



a - Answer QN=12 (7990) Consider the following functional dependencies

a,b -> c,d e,g,h -> f,j

a,c -> b,d p,q -> r,s

e,f,g -> h,i s -> t

f,g -> j q -> u

g,h -> i

Which of the following best describes the relation R(e,f,g,h,i,j)?

a. R is in First Normal Form

b. R is in Second Normal Form

c. R is in Third Normal Form

d. R is in Boyce Codd Normal Form



a

Based on the given functional dependencies {A -> B; B -> A; A -> D; D -> B}, we can derive that
{A} and {B} are both candidate keys for relation R(ABCD). Since all attributes in R are either part
of a candidate key or fully functionally dependent on it, we can conclude that relation R is in
*Third Normal Form (3NF)* - Answer QN=13 (7978) The relation R(ABCD) has following FDs:

{ A -> B ; B -> A ; A -> D ; D -> B }

a. R is in 3NF

, b. R is not in 3NF

c. R is not in 2NF

d. None of the others



a - Answer QN=14 (7976) Given a R(A,B,C,D) with the following FDs:

AB->D

BC->A

AD->B

CD->B

AD->C

Choose a correct statement about R:

a. The FD set of R is not canonical and R is in BCNF

b. The FD set of R is canonical and R is not in BCNF

c. The FD set of R is not canonical and R is not in BCNF



a - Answer QN=15 (7999) What is the difference between the 2NF and the 3NF?

a. 2NF deals with partial functional dependency, while 3NF deals with transitive functional
dependency

b. 2NF deals with transitive functional dependency, while 3NF deals with partial functional
dependency



a - Answer QN=16 (7993) What is "de-normalization"?

a. De-normalization means allowing redundancy in a table

b. De-normalization means allowing duplicate columns appeared in a table

c. De-normalization means allowing a table to have more than 3 columns

d. De-normalization means allowing a table to have more than 1024 columns



b - Answer QN=17 (8004) What is the benefit of "de-normalization"?

a. "de-normalization" has no benefit

b. The main benefit of de-normalization is improved performance with simplified data retrieval
(this is done by reduction in the number of joins needed for data processing)

c. The main benefit of de-normalization is eliminating redundant information from a table and
organizing the data so that future changes to the table are easier



d