EXAM 2

Question 1

Stockflow

Answer 1

association between a resource and an event

Question 2

Participaton

Answer 2

association between an event and an agent

Question 3

Assigned

Answer 3

association between two agents

Question 4

Duality

Answer 4

association between two resources

Question 5

UML stands for

Answer 5

Unified Modeling Language

Question 6

what makes up a class?

Answer 6

stereotype (resource, event, agent)

class name (customer)

attributes (PK, name, address)

Question 7

attributes

Answer 7

Characteristics or elementary properties of classes or associations. They are used for actual communication about the real world phenomena represented by objects

Question 8

minimum multiplicities

Answer 8

can class A exist in the database without class B?

Question 9

maximum multiplicites

Answer 9

can one instance of class A in the database be associated with more than one instance of class B?

Question 10

conceptual model

Answer 10

written one, shows min and max multiplicities between each class.

(no posting of FK, create tables for SF or duplicity but do not post any PKs to them!)

Question 11

logical model

Answer 11

relational table, still not in any software

each class written out with attributes next to it horizontally.
(underline PK, *FK)

you go to logical when you make decisions on how to implement the database

Question 12

physical model

Answer 12

we’ve made the decision on what database we’re using.

(data input into Access to show relationships)

(used as a prototype)

Question 13

Basic constructs of UML

Answer 13

1. class
2. attribute
3. association
4. multiplicity (cardinality)

Question 14

UML is also known as

Answer 14

conceptual (semantic) modeling

Question 15

Object Management Group (OMG)

Answer 15

entity that gives the standards for UML

Question 16

static attributes

Answer 16

will not change if new data is entered into system

Question 17

volatile attributes

Answer 17

will change if new data is entered into system

Question 18

relational database

Answer 18

consists of tables (relations) that are linked together via the use of primary and foreign keys

made up of rows (extensions, instances, records),
and columns (table intensions, facts about the collected records)

Question 19

entity integrity

Answer 19

each row in a table must have a primary key value (and the primary key values must be unique for each row in the table)

PK cannot contain a null value!

Question 20

referential integrity

Answer 20

A value for a foreign key in a table must either:

-Match exactly a value for the primary key in the table from which it was posted

• Be null (no data value – note that this is not a zero) IF the related multiplicity allows

Question 21

one fact, one place

Answer 21

Fact = a pairing of a candidate key attribute value with another attribute value