ISYS 209 FINAL EXAM NEWEST 2026 ACTUAL EXAM|
COMPLETE 250 REAL EXAM QUESTIONS AND
CORRECT VERIFIED ANSWERS/ ALREADY GRADED
A+| ISYS 209 FINAL EXAM REVIEW (MOST RECENT!!)
1. In an entity-relationship (ER) diagram, which symbol
represents an entity?
A) Circle
B) Rectangle
C) Diamond
D) Line
Correct Answer: B
Rationale: In ER diagrams, entities (tables) are represented by
rectangles. Attributes are ovals (or circles), relationships are
diamonds, and lines connect entities to relationships.
2. Which of the following best describes a primary key?
A) A field that allows duplicate values
B) A field that uniquely identifies each record in a table
C) A field that can be null
D) A field that references another table
1
,Correct Answer: B
Rationale: A primary key uniquely identifies each row/record in
a table. It must contain unique, non-null values. Option D
describes a foreign key.
3. A foreign key in a table must match which of the following
in another table?
A) Any indexed column
B) A primary key or unique key
C) Any column with the same name
D) A column that allows nulls
Correct Answer: B
Rationale: A foreign key references a primary key or unique
key in another table to enforce referential integrity. It does not
require matching column names.
4. What is the main purpose of normalization in database
design?
A) To increase data redundancy
B) To reduce data redundancy and avoid update anomalies
C) To make queries run faster
D) To encrypt sensitive data
2
,Correct Answer: B
Rationale: Normalization organizes data to minimize
redundancy and eliminate anomalies (insertion, update, deletion
anomalies). Performance may sometimes decrease, not increase.
5. Which normal form requires that all non-key attributes be
fully functionally dependent on the entire primary key (no
partial dependencies)?
A) First normal form (1NF)
B) Second normal form (2NF)
C) Third normal form (3NF)
D) Boyce-Codd normal form (BCNF)
Correct Answer: B
Rationale: 2NF eliminates partial dependencies (where a non-
key attribute depends on only part of a composite primary key).
1NF eliminates repeating groups. 3NF eliminates transitive
dependencies.
6. A table is in 1NF if it contains:
A) No repeating groups
B) No partial dependencies
C) No transitive dependencies
D) No foreign keys
3
, Correct Answer: A
Rationale: First normal form (1NF) requires that each column
contains atomic (indivisible) values and there are no repeating
groups or arrays. Partial dependencies (B) are addressed in
2NF. Transitive dependencies (C) are addressed in 3NF.
7. Which relationship type is represented by a diamond
labeled "Enrolls" between STUDENT and COURSE entities?
A) One-to-one
B) One-to-many
C) Many-to-many
D) Recursive
Correct Answer: C
Rationale: A many-to-many relationship (e.g., students enroll in
courses) is represented by a diamond. It is typically resolved into
an associative table in implementation.
8. In an ER diagram, an attribute that can be further broken
down into smaller sub-attributes (e.g., Address broken into
Street, City, Zip) is called:
A) Composite attribute
B) Derived attribute
4
COMPLETE 250 REAL EXAM QUESTIONS AND
CORRECT VERIFIED ANSWERS/ ALREADY GRADED
A+| ISYS 209 FINAL EXAM REVIEW (MOST RECENT!!)
1. In an entity-relationship (ER) diagram, which symbol
represents an entity?
A) Circle
B) Rectangle
C) Diamond
D) Line
Correct Answer: B
Rationale: In ER diagrams, entities (tables) are represented by
rectangles. Attributes are ovals (or circles), relationships are
diamonds, and lines connect entities to relationships.
2. Which of the following best describes a primary key?
A) A field that allows duplicate values
B) A field that uniquely identifies each record in a table
C) A field that can be null
D) A field that references another table
1
,Correct Answer: B
Rationale: A primary key uniquely identifies each row/record in
a table. It must contain unique, non-null values. Option D
describes a foreign key.
3. A foreign key in a table must match which of the following
in another table?
A) Any indexed column
B) A primary key or unique key
C) Any column with the same name
D) A column that allows nulls
Correct Answer: B
Rationale: A foreign key references a primary key or unique
key in another table to enforce referential integrity. It does not
require matching column names.
4. What is the main purpose of normalization in database
design?
A) To increase data redundancy
B) To reduce data redundancy and avoid update anomalies
C) To make queries run faster
D) To encrypt sensitive data
2
,Correct Answer: B
Rationale: Normalization organizes data to minimize
redundancy and eliminate anomalies (insertion, update, deletion
anomalies). Performance may sometimes decrease, not increase.
5. Which normal form requires that all non-key attributes be
fully functionally dependent on the entire primary key (no
partial dependencies)?
A) First normal form (1NF)
B) Second normal form (2NF)
C) Third normal form (3NF)
D) Boyce-Codd normal form (BCNF)
Correct Answer: B
Rationale: 2NF eliminates partial dependencies (where a non-
key attribute depends on only part of a composite primary key).
1NF eliminates repeating groups. 3NF eliminates transitive
dependencies.
6. A table is in 1NF if it contains:
A) No repeating groups
B) No partial dependencies
C) No transitive dependencies
D) No foreign keys
3
, Correct Answer: A
Rationale: First normal form (1NF) requires that each column
contains atomic (indivisible) values and there are no repeating
groups or arrays. Partial dependencies (B) are addressed in
2NF. Transitive dependencies (C) are addressed in 3NF.
7. Which relationship type is represented by a diamond
labeled "Enrolls" between STUDENT and COURSE entities?
A) One-to-one
B) One-to-many
C) Many-to-many
D) Recursive
Correct Answer: C
Rationale: A many-to-many relationship (e.g., students enroll in
courses) is represented by a diamond. It is typically resolved into
an associative table in implementation.
8. In an ER diagram, an attribute that can be further broken
down into smaller sub-attributes (e.g., Address broken into
Street, City, Zip) is called:
A) Composite attribute
B) Derived attribute
4
