Chapter 17: Database Design Using the REA Data Model Flashcards
data modeling
defining a database so that it faithfully represents all key components of an organization’s environment. The objective is to explicitly capture and store data about every business activity the organization wishes to plan, control, or evaluate
entity-relationships (E-R) diagram
a graphical depiction of a database’s contents showing the various entities being modeled and the important relationships among them
entity
anything about which an organization wants to collect and store information
REA data model
a data model used to design AIS databases. It contains information about three fundamental types of entities: resources, events, and agents
resources
those things that have economic value to an organization such as cash, inventory, supplies, factories, and land
events
business activities about which management wants to collect information for planning or control purposes
agents
the people and organizations who participate in events and about whom information is desired
cardinalities
describe the nature of a database relationship indicating the number of occurrences of one entity that may be associated with a single occurrence of the other entity. Three types of cardinalities are one-to-one, one-to-many, and many-to-many
minimum cardinality
the minimum number of instances that an entity can be linked to the other entity in the relationship. Only two options: 0 and 1
maximum cardinality
the maximum number of instances that an entity can be linked to the other entity in the relationships. Only two options: 1 to many
one-on-one (1:1) relationship
a relationship between two entities where the maximum cardinality for each entity is 1
one-to-many (1:N) relationship
a relationship between two entities where the maximum cardinality for one of the entities is 1 but the other entity has a maximum cardinality of many
many-to-many (M:N) relationship
a relationship between two entities where the maximum cardinality of both entities is many
