UGC NET CSE | December 2014 | Part 2 | Question: 18

Question

What kind of mechanism is to be taken into account for converting a weak entity set into strong entity set in entity-relationship diagram

• A. Generalization 
• B. Aggregation 
• C. Specialization
• D. Adding suitable attributes 

Answer 1

We can convert weak entity set to strong entity set by adding primary keys of strong entity to the weak entity.This approach causes redundancy storing the primary keys more than once.

Existence of weak entity set depends on Existence of strong entity set,Hence if strong entity set is deleted,weak entity set is also get deleted.Thus if database contains a entity set that depends on another entity set, then it is necessary to mark such as weak entity set.

Hence,Option(D)adding suitable attribute.

Reference:-https://books.google.co.in/books?id=Laakn2aBBLoC&pg=SL16-PA24&lpg=SL16-PA24&dq=how+to+convert+weak+entity+to+strong+entity+set+to+strong+entity+set&source=bl&ots=N5BU6byhmd&sig=ei3TU83MJe1Gt9NZIGqdSZqtFg0&hl=en&sa=X&ved=0ahUKEwiip4LQmYPOAhUdSY8KHbraAEMQ6AEIPTAG#v=onepage&q=how%20to%20convert%20weak%20entity%20to%20strong%20entity%20set%20to%20strong%20entity%20set&f=false

Answer 2

The answer is D.

Though weak entity set can be converted into the strong entity set by simply adding appropriate attributes, this approach results in the redundant storage of primary key.

Answer 3

(D)Adding suitable attributes ..

 

A member of a weak entity is called a subordinate entity…

For converting a weak entity set into strong entity set in entity-relationship diagram by simply adding appropriate attributes...