1. a) (5 points) Consider the following relational mapping of a specialization with 1 superclass entity and n subclass entities:

i) A single relational table that has all attributes of the superclass entity and the subclass entities, i.e. 1 table total.

ii) One relation for each subclass entity that includes the attributes of that subclass entity as well as the attributes of the superclass entity, i.e. n tables total.

iii) One relation for each of the entities, i.e. the subclass entities as well as the superclass entity, i.e. n+1 table total.

In the following table, state if the solution is consistent or inconsistent with the constraint. If additions are necessary, state what they are.

	mandatory, disjoint	optional, disjoint	mandatory, overlapping	optional, overlapping
i
ii
iii

b) (5 points) Answer the following questions.

	What query lists all attributes in a single table?	Rank speed of producing table of all attributes
i
ii
iii

2. Consider the following EER diagram

a) (2 points) Assume that the specialization is optional. What does that mean for the miniworld, and do you think it is appropriate?

b) (2 points) Assume that the specialization is overlapping? What does that mean for the miniworld, and do you think it is appropriate?

c) (6 points) Draw TWO possible relational schemas that are consistent with this EER-diagram and relate them to the alternatives in question 3. Are both of your choices consistent with the assumptions in a) and b)?