Analyzing Weak Entity Set Identification and Participation

This section analyzes the truthfulness of the two statements regarding weak entity sets in database design.

Statement (i): Weak Entity Identification

Statement (i) claims that a weak entity set is identified solely by its partial key (discriminator). This is incorrect.

• A weak entity set depends on an owner entity set for its identification.
• While the partial key (discriminator) uniquely identifies weak entities within a specific owner entity, the complete identification requires both the partial key and the primary key of the associated owner entity.
• Without the owner's key, the partial key alone cannot guarantee uniqueness across the entire database.

Statement (ii): Identifying Relationship Participation

Statement (ii) states that the identifying relationship type between a weak entity type and its owner entity type must have total participation from the weak entity type. This is correct.

• By definition, a weak entity cannot exist independently of its owner entity.
• Every instance of a weak entity must be associated with at least one instance of its owner entity through the identifying relationship.
• This mandatory association signifies total participation. If the owner is removed, the weak entity must also be removed.

Conclusion on Statements

Based on the analysis:

• Statement (i) is FALSE.
• Statement (ii) is TRUE.

Therefore, the only true statement is (ii).

Final Answer Selection

The option that correctly identifies only statement (ii) as true is the correct choice.

The correct option is: Only (ii).