Question

In the context of owner and weak entity sets in the ER (Entity-Relationship) data model, which one of the following statements is TRUE?

• A. The weak entity set MUST have total participation in the identifying relationship
• B. The owner entity set MUST have total participation in the identifying relationship
• C. Both weak and owner entity sets MUST have total participation in the identifying relationship
• D. Neither weak entity set nor owner entity set MUST have total participation in the identifying relationship

Hint:

In the ER model, always associate a weak entity set with an identifying relationship involving its owner entity set for complete design.

Answer 1

The Correct Option is A

In the ER model, a weak entity set cannot exist without being associated with an owner entity set. This dependency requires a weak entity set to have total participation in the identifying relationship, meaning every instance of a weak entity must be related to at least one instance of the owner entity set. Step 1: Analyze the other options.
(B) The owner entity set does not require total participation in the identifying relationship.
(C) Both sets do not need total participation; only the weak entity set does.
(D) This is incorrect because the weak entity set must have total participation.
Conclusion: The weak entity set must have total participation in the identifying relationship, making (A) the correct answer. Final Answer: \[ \boxed{\text{The weak entity set MUST have total participation}} \]