BSCS : Database Management Systems 5

Question 1

Which technique does MVCC (Multi-Version Concurrency Control) use to improve concurrency?

Accepted Answer

Keeping multiple versions of data so readers don't block writers

Answer

MVCC maintains multiple data versions so readers see a consistent snapshot without blocking concurrent writers.

Question 2

A stored procedure in SQL differs from a function primarily because a stored procedure:

Accepted Answer

Can return multiple result sets and does not have to return a value

Answer

Stored procedures can return multiple result sets, execute DML statements, and are not required to return a single value like functions.

Question 3

In the context of functional dependencies, Armstrong's Axioms include which three rules?

Accepted Answer

Reflexivity, Augmentation, Transitivity

Answer

Armstrong's Axioms (Reflexivity, Augmentation, Transitivity) form a sound and complete set of inference rules for functional dependencies.

Question 4

Which type of SQL trigger fires once for the entire DML statement rather than once per affected row?

Accepted Answer

Statement-level trigger

Answer

A statement-level trigger executes once per triggering SQL statement regardless of how many rows are affected.

Question 5

In a star schema, dimension tables are connected to the fact table through:

Accepted Answer

Foreign keys in the fact table referencing dimension primary keys

Answer

In a star schema, the fact table holds foreign keys that each reference the primary key of a single dimension table.

BSCS - Bachelor of Science in Computer Science Practice Test