Which of the following notations in an E-R diagram means that the entity is optional and a relationship need not have an entity of that type?
A)vertical bar
B)arrow
C)double line
D)small oval

Question

Quizplus · Accepted Answer

The small oval notation in an E-R diagram represents an optional entity. This means that the entity may or may not exist in a relationship, and the relationship can still be valid without the entity of that type. The other notations listed (vertical bar, arrow, and double line) do not represent optional entities.

Which of the Following Notations in an E-R Diagram Means