Question

The primary key is chosen from ________.

• A. The most complex candidate key available.
• B. All available candidate keys for a table
• C. The simplest candidate key available.
• D. Any attribute within the table

Answer 1

The Correct Option is C

The correct answer is (3) The simplest candidate key available. 

Candidate Key: A candidate key is a column or set of columns that can uniquely identify each row in a table. 

Primary Key: A primary key is a specific candidate key chosen as the main identifier for the table. 

The selection criteria are generally based on: 

• Uniqueness: Must uniquely identify each record. 
• Minimal: Should be the smallest set of attributes that still ensures uniqueness. 
• Simplicity: Easy to understand and work with. 
• Stability: Should rarely or never change its value. 

Therefore, the simplest candidate key that fulfills the requirement of uniqueness is preferred as the primary key for ease of use, performance, and reduced storage space.