Advanced ER Modeling

Question 1

Typing class

Answer 1

strong, abstract entity class that defines the attribute characteristics for another entity class

Question 2

Instantiation class

Answer 2

inherit the attributes of a supertype, including the identifier

Question 3

Do the instantiation class members have their own identifiers?

Answer 3

Yes

Question 4

What is the difference of a type/instance compared to weak e.c and a subclass?

Answer 4

Type & instantiations are different entities and require different attributes to identify

Question 5

How are type/instance attribute inheritance and relationship inheritance different than weak e.c and subclasses?

Answer 5

Inherits common attributes from the typing class and constraining relationships of the typing class restrict the domains for instantiations

Question 6

Aggregate entity instance

Answer 6

collection of entities from one or more (other) entity classes

Question 7

Aggregate entity class

Answer 7

collection of aggregate entity instances

Question 8

What are the attributes of an aggregate class

Answer 8

identifier

multi-valued attribute “Contents”

Question 9

What is entity class cardinality

Answer 9

restricts the number of members in an entity class

Question 10

What is attribute cardinality

Answer 10

restricts the number of values that an attribute for an entity instance can take

Question 11

What is domain cardinality

Answer 11

restricts the number of values for the domain of the attribute

Question 12

Participation cardinality

Answer 12

How many times can a single entity participate in a relationship or how many times can a set of entities participate in a relationship

Question 13

Co-occurrence cardinality

Answer 13

for a given entity, how many different (distinct) members of another entity class can co-occur with it?