Chapter 4 Flash Cards
Binary Relationship
Two entities are associated.
Cardinality
Expresses the minimum and maximum number of entity occurrences associated with one occurrence of related entity
Composite Attribute
Attribute that can be subdivided to yield additional attributes.
Composite Identifier
Primary key composed of more than one attribute.
Connectivity
Describes the relationship classification. (1:1, M:N, 1:M)
Derived Attribute
Attribute whose value is calculated from other attributes
Existence-Dependent
Entity exists in the database only when it is associated with another related entity occurrence. AKA Strong Entity or Regular Entity.
Existence-Independent
Entity exists apart from all of its related entities.
Identifiers
One or more attributes that uniquely identify each entity instance.
Iterative Process
Based on repetition of processes and procedures.
Mandatory Participation
One entity occurrence requires a corresponding entity occurrence in a particular relationship.
Multivalued Attributes
Attributes that have many values. Need to create either several new attributes or a new entity composed of original multivalued attribute’s components.
Optional Attribute
Does not require a value, can be left empty.
Optional Participation
One entity occurrence does not require a corresponding entity occurrence in a particular relationship.
Participants
Entities that participate in a relationship
Recursive Relationship
Relationship exists between occurrences of the same entity set.
Relational Schema
The organization of a relational database as described by the database administrator.
Relationship Degree
Indicates the number of entities or participants associated with a relationship
Required Attribute
Must have a value, cannot be left empty.
Simple Attribute
Attribute that cannot be subdivided.
Single-Valued Attribute
Attribute that has only a single value.
Strong (Identifying Relationship) Relationship
Primary key of the related entity contains a primary key component of the parent entity.
Ternary Relationship
Three entities are associated.
Unary Relationship
Association is maintained within a single entity.
Weak Entity
An entity that is existence-dependent and has a primary key that is partially or totally derived from parent entity in the relationship
Weak (Non-Identifying Relationship) Relationship
Primary key of the related entity does not contain a primary key component of the parent entity.
