Artificial key meaning in databases

Question

What is the meaning of "artificial key" of an entity set in database design?Is it an attribute that is not natural to the entity set?Is it something assigned by a "global organization"?For example: Social Insurance number. Can you provide some brief examples?

Answer 1

An artificial key has no significance to the business or company.

Artificial keys are allowed when:

1) No attribute has all the primitive key characteristics.

2) The primitive key is complex and large.

Example: Entry table from a business point of view has (employee, department) combination as primary key.

But this primary key is extensive and complex, so DBA chooses to add emp_id column as primary key. Here, emp_id can also be termed as Artificial Key.