Data Processing Database Management Systems 1 — Questions and Answers
Question 1: What does DBMS stand for?
- Database Management System (Correct answer)
- Data Backup Management Service
- Digital Binary Memory Storage
- Distributed Buffer Management System
Correct answer: Database Management System
DBMS stands for Database Management System, software that enables users to define, create, maintain, and control access to a database.
Question 2: Which SQL statement is used to retrieve data from a database?
- SELECT (Correct answer)
- INSERT
- UPDATE
- DELETE
Correct answer: SELECT
The SELECT statement is used in SQL to query and retrieve data from one or more tables in a relational database.
Question 3: What is a primary key in a relational database?
- A unique identifier for each record in a table (Correct answer)
- The first column in every table
- A field that stores encrypted passwords
- A link between two databases
Correct answer: A unique identifier for each record in a table
A primary key is a column or set of columns whose values uniquely identify each row in a database table.
Question 4: Which normal form eliminates partial dependencies in a relational database?
- Second Normal Form (2NF) (Correct answer)
- First Normal Form (1NF)
- Third Normal Form (3NF)
- Boyce-Codd Normal Form (BCNF)
Correct answer: Second Normal Form (2NF)
Second Normal Form (2NF) requires that every non-key attribute is fully functionally dependent on the entire primary key, eliminating partial dependencies.
Question 5: What is the role of an index in a database?
- To speed up data retrieval operations on a table (Correct answer)
- To store backup copies of data
- To encrypt sensitive columns
- To define access permissions for users
Correct answer: To speed up data retrieval operations on a table
A database index is a data structure that improves the speed of data retrieval by providing quick access paths to rows in a table.
Question 6: What does the SQL JOIN clause do?
- Combines rows from two or more tables based on a related column (Correct answer)
- Deletes records from multiple tables at once
- Sorts data in descending order
- Converts data types between columns
Correct answer: Combines rows from two or more tables based on a related column
The JOIN clause is used in SQL to combine rows from two or more tables based on a matching column value, enabling relational queries.
Data Processing Database Management Systems 1
What does DBMS stand for?