What is a business key used for?

What is a business key used for?

• A. To identify numeric data types
• B. To create unique constraints in a database
• C. To retrieve a single entity instance
• D. To link dependent entities

Answer: (C)

A business key is used to retrieve a single entity instance by providing a unique identifier for that particular instance within a business context. Unlike surrogate keys that are artificially created for system operations, the business key is derived from the actual data within the business domain and holds significance to the stakeholders. It typically reflects the natural characteristics of the data and is often a composite of one or more attributes that, when taken together, guarantee the uniqueness of an entity within a given context. In this role, the business key enables effective data retrieval, ensuring that users can access specific records in a meaningful way. For instance, in a customer database, a business key might be a combination of the customer's email address and their phone number, allowing for precise identification of that specific customer without ambiguity. In contrast, options related to numeric data types or unique constraints in a database do not effectively address the core purpose of a business key, which is centered on identification and retrieval of individual entities rather than database structure or types. Similarly, while business keys can be useful in linking dependent entities, that is not their primary function; linking is often facilitated through foreign keys or other relational methods that connect records across tables.

A business key is used to retrieve a single entity instance by providing a unique identifier for that particular instance within a business context. Unlike surrogate keys that are artificially created for system operations, the business key is derived from the actual data within the business domain and holds significance to the stakeholders. It typically reflects the natural characteristics of the data and is often a composite of one or more attributes that, when taken together, guarantee the uniqueness of an entity within a given context.

In this role, the business key enables effective data retrieval, ensuring that users can access specific records in a meaningful way. For instance, in a customer database, a business key might be a combination of the customer's email address and their phone number, allowing for precise identification of that specific customer without ambiguity.

In contrast, options related to numeric data types or unique constraints in a database do not effectively address the core purpose of a business key, which is centered on identification and retrieval of individual entities rather than database structure or types. Similarly, while business keys can be useful in linking dependent entities, that is not their primary function; linking is often facilitated through foreign keys or other relational methods that connect records across tables.