Database System Concepts: Relationship Sets Quiz

It models the same entity set (employee) participating in the relationship set 'supervises' twice, once as the supervisor and once as the supervised employee.

They are called roles.

It is modeled by ordered pairs of course entities, where the first course takes the role of courseC1 and the second takes the role of prerequisite course C2.

<p>To designate sub-groupings within an entity set that are distinctive from other entities in the set.</p> Signup and view all the answers

<p>By a triangle component labeled ISA.</p> Signup and view all the answers

<p>A lower-level entity set inherits all the attributes and relationship participation of the higher-level entity set to which it is linked.</p> Signup and view all the answers

<p>Whether an entity in the higher-level entity set must belong to at least one of the lower-level entity sets within a generalization.</p> Signup and view all the answers

<p>By adding the keyword total in the diagram and drawing a dashed line from the keyword to the corresponding hollow arrow-head to which it applies.</p> Signup and view all the answers

<p>Partial generalization.</p> Signup and view all the answers

<p>All entities in the higher-level entity set must belong to the lower-level entity sets.</p> Signup and view all the answers