AMCAT Computer Science: DBMS Concepts 2

Question 1

Which normal form eliminates transitive dependencies?

Accepted Answer

3NF

Answer

Third Normal Form (3NF) eliminates transitive dependencies where a non-key attribute depends on another non-key attribute.

Question 2

What does ACID stand for in database transactions?

Accepted Answer

Atomicity, Consistency, Isolation, Durability

Answer

ACID = Atomicity (all or nothing), Consistency (valid state), Isolation (concurrent transactions behave serially), Durability (committed data persists).

Question 3

Which SQL clause is used to filter groups after a GROUP BY?

Accepted Answer

HAVING

Answer

HAVING filters groups formed by GROUP BY, whereas WHERE filters individual rows before grouping.

Question 4

Which join returns all rows from both tables, with NULLs where there is no match?

Accepted Answer

FULL OUTER JOIN

Answer

FULL OUTER JOIN returns all rows from both tables, filling NULLs where there is no matching row in the other table.

Question 5

What is the purpose of a foreign key?

Accepted Answer

To enforce referential integrity between tables

Answer

A foreign key enforces referential integrity so that values reference existing rows in the related table.

(AMCAT) Aspiring Minds Computer Adaptive Test Practice Test

(AMCAT) Aspiring Minds Computer Adaptive Test Practice Test

AMCAT Computer Science: DBMS Concepts 2