Chapter 2 Flashcards
Derived Attribute
An attribute whose values can be calculated from related attribute values
Identifying Owner
The entity type on which the weak entity type depends
Weak entity type
An entity type whose existence depends on some other entity type
Relationship Instance
An association between (or among) entity instances here each relationship instance associates exactly one entity type
Attribute
A property or characteristic of an entity or relationship type that is of interest to the organization; property of an entity
Strong Entity type
An entity that exists independently of other entity types
Relationship Type
A meaningful association between (or among) entity types; association between entity types
Fact
An association between two or more terms
Composite attribute
An attribute that has meaningful component parts (attributes); can be broken into component parts
Time Stamp
A time value that is associated with a data value, often indicating when some event occurred that affected the data value
Optional attribute
An attribute that may not have a value for every entity (or relationship) instance with which it is associated
Required attribute
An attribute that must have a value for every entity (or relationship) instance with which it is associated
Binary relationship
A relationship between the instances of two entity types
Maximum Cardinality
The maximum number of instances of one entity that may be associated with each instance of another entity
Ternary relationship
A simultaneous relationship among the instances of three entity types
