CIT 381 Chapter 4, Database Systems: Design, Implementation, and
Management
1. Binary Relationship: An ER term for an association (relationship) between two entities. For example,
PROFESSOR teaches CLASS.
2. Cardinality: A property that assigns a specific value to connectivity and expresses the range of allowed entity
occurrences associated with a single occurrence of the related entity.
3. Composite Attributes: An attribute that can be further subdivided t oyield additional attributes. For
example, a phone number such as 617-896-2368 may be divided into an area code (617), and exchange number
(896), and a four digit code (2368). Compare to simple attribute.
4. Composite Identifier: In ER modeling, a key composed of more than one attribute.
5. Connectivity: The type of relationship between entities. Classifications include 1:1, 1:M , and M:N.
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, 6. Derived Attribute: An attribute that does no physically exist within and entity and is derived via an algorithm.
For example, the Age attribute might be derived by subtracting the birth date from the current day.
7. Existence-Dependent: A property of an entity whose existence depends on one or more other entities.
In such an environment, the existence-independent table must be created and loaded first because the existence
dependent key cannot reference a table that does not yet exist.
8. Existence-Independent: A property of an entity that can exist apart from one or more related entities.
Such a table must be created first when referencing an existence dependent table.
9. Identifier: One or more attributes that uniquely identify each entity instance.
10. Iterative Process: A process based on repetition of steps and procedures.
11. Mandatory Participations: A relationship in which one entity occurrence must have a corresponding
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Management
1. Binary Relationship: An ER term for an association (relationship) between two entities. For example,
PROFESSOR teaches CLASS.
2. Cardinality: A property that assigns a specific value to connectivity and expresses the range of allowed entity
occurrences associated with a single occurrence of the related entity.
3. Composite Attributes: An attribute that can be further subdivided t oyield additional attributes. For
example, a phone number such as 617-896-2368 may be divided into an area code (617), and exchange number
(896), and a four digit code (2368). Compare to simple attribute.
4. Composite Identifier: In ER modeling, a key composed of more than one attribute.
5. Connectivity: The type of relationship between entities. Classifications include 1:1, 1:M , and M:N.
1/2
, 6. Derived Attribute: An attribute that does no physically exist within and entity and is derived via an algorithm.
For example, the Age attribute might be derived by subtracting the birth date from the current day.
7. Existence-Dependent: A property of an entity whose existence depends on one or more other entities.
In such an environment, the existence-independent table must be created and loaded first because the existence
dependent key cannot reference a table that does not yet exist.
8. Existence-Independent: A property of an entity that can exist apart from one or more related entities.
Such a table must be created first when referencing an existence dependent table.
9. Identifier: One or more attributes that uniquely identify each entity instance.
10. Iterative Process: A process based on repetition of steps and procedures.
11. Mandatory Participations: A relationship in which one entity occurrence must have a corresponding
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