Databases (DBMS) Quiz

Question 1

What does the "I" in ACID stand for?

Accepted Answer

Isolation

Answer

Integrity

Answer

Indexing

Answer

Immutability

Question 2

A relation is in 3NF but has a non-prime attribute determined by another non-prime attribute. This violates…

Accepted Answer

nothing — 3NF allows it

Answer

1NF

Answer

2NF

Answer

BCNF

Question 3

Which normal form removes partial dependencies on a composite primary key?

Accepted Answer

2NF

Answer

1NF

Answer

3NF

Answer

BCNF

Question 4

A candidate key is…

Accepted Answer

A minimal set of attributes that uniquely identifies a row

Answer

Any attribute in a table

Answer

The same as a foreign key

Answer

Always a single column

Question 5

What does a database index primarily improve?

Accepted Answer

Read/lookup speed at the cost of extra storage and slower writes

Answer

Write/insert speed

Answer

Storage size

Answer

Transaction isolation

Question 6

Which join returns only rows with matching keys in both tables?

Accepted Answer

INNER JOIN

Answer

LEFT JOIN

Answer

RIGHT JOIN

Answer

FULL OUTER JOIN

Question 7

Which isolation level prevents dirty reads but still allows non-repeatable reads?

Accepted Answer

Read Committed

Answer

Read Uncommitted

Answer

Repeatable Read

Answer

Serializable

Question 8

A foreign key enforces…

Accepted Answer

Referential integrity between two tables

Answer

Uniqueness of a column

Answer

That a column cannot be NULL

Answer

Sorted storage of rows

Question 9

What data structure do most relational database indexes use?

Accepted Answer

B+ tree

Answer

Hash table only

Answer

Binary search tree

Answer

Skip list

Question 10

The "Durability" property guarantees that…

Accepted Answer

Once committed, changes survive crashes and power loss

Answer

Transactions run in isolation

Answer

The database is always consistent

Answer

All-or-nothing execution of a transaction

Databases (DBMS) quiz

What does the "I" in ACID stand for?

More CS Fundamentals quizzes