CS 6400 Chapter 4 UPDATED ACTUAL
Questions and CORRECT Answers
local attributes - CORRECT ANSWER - local to a subclass, not part of the superclass
How is a subset denoted in EER diagrams? - CORRECT ANSWER - a "U"; direct ion of
the "U" determines the superclass
What is the "O" symbol with generalization/specialization diagrams - CORRECT
ANSWER - Deals with potential overlapping of subtypes from the supertype
attribute defined specialization - CORRECT ANSWER - an attribute that defintes the
different subsets
What is the "D" symbol with generalization/specialization diagrams - CORRECT
ANSWER - "disjointness constraint"; signifies that an entity can not overlap into more
than one subset specialization
Total disjoint constraint? - CORRECT ANSWER - all entities in superclass must be in a
subclass (no overlapping)
What is the symbol "U"? - CORRECT ANSWER - Union: used to describe union of two
entities
Will an inner join between two entities show up in a union? - CORRECT ANSWER -
Absolutely not; it will not take in an entity with both properties
Full Union - CORRECT ANSWER - (shown with double connecting lines): holds all
entities in the super class
, objectified relationship type - CORRECT ANSWER - turning a relationship type into a
entity type; done by taking current cardinality and then adding 1 on both sides (N:M = 1:N &
M:1)
Does EER support aggregation? - CORRECT ANSWER -
What are the two types of calculus? - CORRECT ANSWER - tuple and domain calculus
(relational) a relation - CORRECT ANSWER - a subset of the set of ordered n-tuples
degree of the relations - CORRECT ANSWER - the amount of columns in a data set
set of tuples - CORRECT ANSWER - set of rows
difference between a category or union type in EER? - CORRECT ANSWER - They are
the same functionally
Difference between ER and EER models? - CORRECT ANSWER - Super/subclasses and
specializations/generalizations
inheritance - CORRECT ANSWER - inheriting all the attributes of the super class
specific relationship type - CORRECT ANSWER - a relationship that occurs with a
specialization
which EER technique is the reverse process of abstraction? - CORRECT ANSWER -
Generalization
Questions and CORRECT Answers
local attributes - CORRECT ANSWER - local to a subclass, not part of the superclass
How is a subset denoted in EER diagrams? - CORRECT ANSWER - a "U"; direct ion of
the "U" determines the superclass
What is the "O" symbol with generalization/specialization diagrams - CORRECT
ANSWER - Deals with potential overlapping of subtypes from the supertype
attribute defined specialization - CORRECT ANSWER - an attribute that defintes the
different subsets
What is the "D" symbol with generalization/specialization diagrams - CORRECT
ANSWER - "disjointness constraint"; signifies that an entity can not overlap into more
than one subset specialization
Total disjoint constraint? - CORRECT ANSWER - all entities in superclass must be in a
subclass (no overlapping)
What is the symbol "U"? - CORRECT ANSWER - Union: used to describe union of two
entities
Will an inner join between two entities show up in a union? - CORRECT ANSWER -
Absolutely not; it will not take in an entity with both properties
Full Union - CORRECT ANSWER - (shown with double connecting lines): holds all
entities in the super class
, objectified relationship type - CORRECT ANSWER - turning a relationship type into a
entity type; done by taking current cardinality and then adding 1 on both sides (N:M = 1:N &
M:1)
Does EER support aggregation? - CORRECT ANSWER -
What are the two types of calculus? - CORRECT ANSWER - tuple and domain calculus
(relational) a relation - CORRECT ANSWER - a subset of the set of ordered n-tuples
degree of the relations - CORRECT ANSWER - the amount of columns in a data set
set of tuples - CORRECT ANSWER - set of rows
difference between a category or union type in EER? - CORRECT ANSWER - They are
the same functionally
Difference between ER and EER models? - CORRECT ANSWER - Super/subclasses and
specializations/generalizations
inheritance - CORRECT ANSWER - inheriting all the attributes of the super class
specific relationship type - CORRECT ANSWER - a relationship that occurs with a
specialization
which EER technique is the reverse process of abstraction? - CORRECT ANSWER -
Generalization
