Database Fundamentals Chapter 2 Set 1

1. What is a relational database?

• A database that stores data in files

• A database that stores data in tables

• A database that stores data in spreadsheets

• A database that stores data in a hierarchical structure

Answer explanation

A relational database is designed to store data in tables, which allows for efficient organization and retrieval of related data. This structure contrasts with other formats like files, spreadsheets, or hierarchical systems.

2. What does RDBMS stand for?

• Relational Data Model System

• Relational Database Management System

• Relational Data Binary System

• Relational Database Monitoring System

Answer explanation

RDBMS stands for Relational Database Management System, which is a type of database management system that stores data in a structured format using rows and columns. The other options do not accurately describe this concept.

3. Which of the following is NOT a popular RDBMS package?

• Oracle

• MySQL

• Microsoft SQL Server

• Excel

Answer explanation

Excel is primarily a spreadsheet application, not a relational database management system (RDBMS). In contrast, Oracle, MySQL, and Microsoft SQL Server are all well-known RDBMS packages.

4. What is a relation in a relational database?

• A field

• A table

• A row

• A key

Answer explanation

In a relational database, a relation is represented as a table. Each table consists of rows and columns, where rows represent records and columns represent fields. Therefore, the correct answer is 'A table'.

5. What does a tuple in a relational database represent?

• A column

• A row

• A table

• A key

Answer explanation

In a relational database, a tuple represents a row. Each tuple contains a set of values corresponding to the attributes defined by the table's columns, making 'A row' the correct answer.

6. The number of rows in a relation is known as its:

• Degree

• Cardinality

• Attribute

• Domain

Answer explanation

The number of rows in a relation is referred to as its cardinality. In contrast, degree refers to the number of attributes, while attribute and domain relate to the properties of the data itself.

7. In a relational database, an attribute refers to:

• A row

• A column

• A table

• A key

Answer explanation

In a relational database, an attribute is synonymous with a column. It represents a specific piece of data within a table, while a row represents a record, and a table is a collection of rows and columns.

8. The degree of a relation is defined as:

• The number of rows in the table

• The number of columns in the table

• The number of keys in the table

• The number of tables in the database

Answer explanation

The degree of a relation in a database refers to the number of columns in the table. This is a fundamental concept in relational database design, distinguishing it from other attributes like rows or keys.

9. Which of the following is a unique identifier for each record in a table?

• Foreign key

• Candidate key

• Primary key

• Domain

Answer explanation

The primary key is a unique identifier for each record in a table, ensuring that no two records can have the same value in this field. Other options like foreign key and candidate key do not serve this unique identification purpose.

10. What does the domain of an attribute represent?

• The name of the attribute

• The number of rows in the table

• The pool of valid values for an attribute

• The type of the database

Answer explanation

The domain of an attribute defines the set of valid values that the attribute can take. This ensures data integrity by restricting the values to a specific range or type, making 'the pool of valid values for an attribute' the correct choice.