Data Processing Database Management Systems 3

Question 1

What is the purpose of database normalization?

Accepted Answer

To reduce data redundancy and improve data integrity

Answer

Database normalization organizes tables to minimize redundancy and dependency, ensuring data is stored logically and efficiently.

Question 2

Which SQL command permanently removes a table and all its data from a database?

Accepted Answer

DROP TABLE

Answer

DROP TABLE removes the entire table definition and all its data, constraints, and indexes permanently from the database.

Question 3

What is a view in SQL?

Accepted Answer

A virtual table based on the result of a SELECT query

Answer

A SQL view is a stored query that appears and behaves like a virtual table, providing a simplified or restricted window into underlying data.

Question 4

What does the GROUP BY clause do in SQL?

Accepted Answer

Groups rows sharing a common value into summary rows for aggregate functions

Answer

The GROUP BY clause groups rows that have the same values in specified columns, enabling aggregate functions like COUNT, SUM, and AVG.

Question 5

What is a NoSQL database?

Accepted Answer

A non-relational database that stores data in formats like documents, key-value pairs, or graphs

Answer

NoSQL databases are non-relational data stores designed for flexible schemas, horizontal scaling, and high-volume unstructured or semi-structured data.

Data Processing Practice Test

Data Processing Practice Test

Data Processing Database Management Systems 3