Question 1
Which of the following is a type of NoSQL database?
A
Document-oriented
B
Relational
C
Object-oriented
D
Hierarchical
Question 2
What does the SQL UNION operator do?
A
Combines the result-set of two or more SELECT statements
B
Finds the common records between two tables
C
Finds records in one table but not another
D
Joins tables based on a foreign key
Question 3
What does a LEFT JOIN return?
A
All records from the right table and matched records from the left
B
All records from both tables
C
Matched records from both tables
D
All records from the left table and matched records from the right
Question 4
What is an entity in an ER diagram?
A
An object or concept about which data is collected
B
A relationship between two tables
C
An action performed by a user
D
A query result
Question 5
Which type of lock allows multiple transactions to read an item but not update it?
A
Exclusive lock
B
Shared lock
C
Deadlock
D
Binary lock