- Courses
- Tutorials
- Interview Prep
Keys & Constraints in DBMS
Question 1
What is the main purpose of keys in a DBMS?
To increase redundancy
To uniquely identify records and maintain data integrity
To compress data
To sort records alphabetically
Question 2
Which of the following can be classified as a super key?
Only STUD_NO
Only PHONE
STUD_NO + SNAME
Only SNAME
Question 3
What makes a candidate key different from a super key?
It can contain NULLs
It includes all columns of the table
It is a minimal super key with no unnecessary attributes
It must be the same as the primary key
Question 4
Which of the following cannot be NULL?
Foreign key
Candidate key
Primary key
Both B and C
Question 5
Which of the following is NOT an integrity constraint in DBMS?
Domain Constraint
Referential Integrity
Behavioral Constraint
Key Constraint
Question 6
Which of the following constraints ensures that no two rows have the same value in a specified column or set of columns?
Foreign Key Constraint
Domain Constraint
Key Constraint
Referential Integrity Constraint
Question 7
Which of the following constraints can be used to define rules that involve multiple tables or complex conditions?
Check Constraint
Assertion
Trigger
Default
Question 8
Referential integrity ensures that a foreign key:
Must always be unique
Must be NULL
Must either match a primary key or be NULL
Must have a default value
Question 9
In the Top-Down strategy of schema design, the design process begins with:
Specific attributes of entity types
Physical storage details
A high-level conceptual schema
Generalized relationships
Question 10
In the Mixed strategy of schema design:
Only Top-Down methods are used
Normalization is avoided
Top-Down and Bottom-Up are combined
Only foreign keys are defined initially
There are 10 questions to complete.