Which of the following describes how domains are defined?

Which of the following describes how domains are defined?

• A. Only through primary keys
• B. As an abstract concept with no real application
• C. By data type, data format, list, range, and rule-based
• D. All attributes must be numeric

Answer: (C)

Domains in data management are defined as specific sets of values that a particular attribute can hold. This includes characteristics such as data type (e.g., integer, string, date), data format (e.g., email address format, phone number format), a predefined list of acceptable values, a defined range of values (e.g., 1-100), and any other rules that might apply to those values (e.g., must be unique, must not be null). By establishing these criteria, domains ensure data integrity and consistency across datasets. The other options do not effectively capture the comprehensive nature of how domains are defined. Designing domains based solely on primary keys misses the broader context of data validation and constraints that other attributes can have. Describing domains as an abstract concept misrepresents their practical application in designing databases and ensuring data quality. Finally, the idea that all attributes must be numeric does not reflect the variety of data types that domains can define; domains can encompass text, dates, and other non-numeric types as well.

Domains in data management are defined as specific sets of values that a particular attribute can hold. This includes characteristics such as data type (e.g., integer, string, date), data format (e.g., email address format, phone number format), a predefined list of acceptable values, a defined range of values (e.g., 1-100), and any other rules that might apply to those values (e.g., must be unique, must not be null). By establishing these criteria, domains ensure data integrity and consistency across datasets.

The other options do not effectively capture the comprehensive nature of how domains are defined. Designing domains based solely on primary keys misses the broader context of data validation and constraints that other attributes can have. Describing domains as an abstract concept misrepresents their practical application in designing databases and ensuring data quality. Finally, the idea that all attributes must be numeric does not reflect the variety of data types that domains can define; domains can encompass text, dates, and other non-numeric types as well.