Database Fundamentals Chapter 2 Set 2

Demonstrating the purpose of an RDBMS involves which of the following? [CLO1, C3]

• A. Managing relationships between various database systems.

• B. Storing and retrieving data from multiple flat files.

• C. Providing a systematic way to store, manage, and retrieve relational data.

• D. Organizing unstructured data into a hierarchical model.

Answer explanation

The purpose of an RDBMS is to provide a systematic way to store, manage, and retrieve relational data, making option C the correct choice. Other options do not accurately reflect the core function of an RDBMS.

Identifying the key features of popular RDBMS packages involves which of the following? [CLO1, C3]

• A. Finding the version number of the software.

• B. Demonstrating their ability to handle large datasets.

• C. Using only the software with graphical user interfaces.

• D. Measuring their popularity based on online reviews.

Answer explanation

The correct choice is B, as popular RDBMS packages must demonstrate their ability to handle large datasets, which is a critical feature for performance and scalability in database management.

Constructing a relation in a relational database involves which of the following components? [CLO1, C3]

• A. Columns, rows, and keys.

• B. Only keys and constraints.

• C. Tables and spreadsheets.

• D. Metadata and schemas.

Answer explanation

Constructing a relation in a relational database requires columns (attributes), rows (records), and keys (unique identifiers). Therefore, the correct choice is A, as it encompasses all essential components.

Calculating the cardinality of a relation refers to which of the following? [CLO1, C3]

• A. The number of columns in a table.

• B. The number of primary keys.

• C. The number of rows in a table.

• D. The number of relationships between tables.

Answer explanation

The cardinality of a relation specifically refers to the number of rows in a table, making option C the correct choice. Options A, B, and D refer to different aspects of database structure.

Demonstrating the use of a primary key in a table involves which of the following? [CLO1, C3]

• A. Finding a unique identifier for each record.

• B. Using a random value for each record.

• C. Storing redundant data in a table.

• D. Manipulating all values within a column.

Answer explanation

A primary key uniquely identifies each record in a table, ensuring no duplicates. Therefore, finding a unique identifier for each record (Choice A) is essential, while the other options do not align with the purpose of a primary key.

Drawing up a relation schema requires which of the following? [CLO1, C3]

• A. Writing SQL code for queries.

• B. Demonstrating the logical structure of a database.

• C. Preparing user interface designs.

• D. Operating multiple database instances.

Answer explanation

Drawing up a relation schema involves demonstrating the logical structure of a database, which defines how data is organized and related. This is essential for effective database design, making option B the correct choice.

Explaining how domains are used in relational databases involves which of the following? [CLO1, C3]

• A. Estimating the data type for attributes.

• B. Finding appropriate values for the attributes of a relation.

• C. Discovering new relations between tables.

• D. Demonstrating the hierarchical structure of data.

Answer explanation

Domains in relational databases define the permissible values for attributes. Thus, finding appropriate values for the attributes of a relation is essential, making option B the correct choice.

Using relation instances helps in which of the following? [CLO1, C3]

• A. Verifying the integrity of a database schema.

• B. Demonstrating the effect of various constraints.

• C. Constructing queries for dynamic data retrieval.

• D. Manipulating the data in different scenarios.

Answer explanation

Using relation instances is crucial for manipulating data in various scenarios, as it allows users to test different data conditions and observe outcomes, making option D the correct choice.

Finding the most critical component in a relation key involves which of the following? [CLO1, C3]

• A. Primary Key

• B. Candidate Key

• C. Foreign Key

• D. Secondary Key

Answer explanation

The primary key is the most critical component in a relation key as it uniquely identifies each record in a table. Unlike candidate keys, foreign keys, or secondary keys, the primary key ensures data integrity and uniqueness.

Demonstrating the entity integrity rule means ensuring which of the following? [CLO1, C3]

• A. All values are non-NULL in a primary key column.

• B. All rows have different values in every column.

• C. No duplicates exist in the entire database.

• D. Referential integrity between tables is maintained.

Answer explanation

The entity integrity rule requires that all values in a primary key column must be non-NULL, ensuring that each row can be uniquely identified. Therefore, the correct answer is A.