Term
| The property of _____ enables an entity subtype to inherit the attributes and relationships of the supertype. |
|
Definition
|
|
Term
| A total completeness constraint is represented by a _____. |
|
Definition
| double horizontal line under a circle |
|
|
Term
| A specialization hierarchy can have _____ level(s) of supertype/subtype relationships. |
|
Definition
|
|
Term
| Within a specialization hierarchy, a supertype can exist only within the context of a subtype. |
|
Definition
|
|
Term
| The purpose of an entity _____ is to simplify an entity-relationship diagram (ERD) and thus enhance its readability. |
|
Definition
|
|
Term
| A subtype contains attributes that are common to all of its supertypes. |
|
Definition
|
|
Term
| Entity supertypes and subtypes are organized in a specialization hierarchy. |
|
Definition
|
|
Term
| Entity subtypes do not inherit the relationships in which the supertype entity participates. |
|
Definition
|
|
Term
| At the implementation level, the supertype and its subtype(s) depicted in the specialization hierarchy maintain a 1:1 relationship. |
|
Definition
|
|
Term
| The entity supertype contains common characteristics, and the entity subtypes each contain their own unique characteristics |
|
Definition
|
|
Term
| The “_____” characteristic of a primary key states that the selected primary key must not be composed of any attribute(s) that might be considered a violation. |
|
Definition
|
|
Term
| The property of a subtype discriminator enables an entity supertype to inherit the attributes and relationships of the subtype. |
|
Definition
|
|
Term
| The “_____” characteristic of a primary key states that the primary key should not have embedded semantic meaning. |
|
Definition
|
|
Term
| Specialization is the top-down process of identifying lower-level, more specific entity subtypes from a higher-level entity supertype. |
|
Definition
|
|
Term
| At the implementation level, the supertype and its subtype(s) depicted in the specialization hierarchy maintain a 1:1 relationship. |
|
Definition
|
|
Term
| An entity supertype can have disjoint or overlapping entity subtypes. |
|
Definition
|
|
Term
| The _____ depicts the arrangement of higher-level entity supertypes (parent entities) and lower-level entity subtypes (child entities). |
|
Definition
|
|
Term
| In the context of total completeness, in a(n) _____, every supertype occurrence is a member of at least one subtype. |
|
Definition
|
|
Term
| A(n) _____ is the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related. |
|
Definition
|
|
Term
| Entity subtypes do not inherit the relationships in which the supertype entity participates. |
|
Definition
|
|
Term
| A partial completeness constraint is represented by _____. |
|
Definition
| a single horizontal line under a circle |
|
|
Term
| At the implementation level, the supertype and its subtype(s) depicted in the specialization hierarchy maintain a 1:1 relationship. |
|
Definition
|
|
Term
| Entity supertypes and subtypes are organized in a specialization hierarchy. |
|
Definition
|
|
Term
| The extended entity relationship model (EERM) is sometimes referred to as the _____. |
|
Definition
| enhanced entity relationship model |
|
|
Term
| The “_____” characteristic of a primary key states that the primary key must uniquely identify each entity instance, must be able to guarantee unique values, and must not contain nulls. |
|
Definition
|
|
Term
| An entity cluster is formed by combining multiple interrelated entities into _____. |
|
Definition
| a single abstract entity object |
|
|
Term
| One important inheritance characteristic is that all entity subtypes inherit their _____ key attribute from their supertype. |
|
Definition
|
|
Term
| An entity supertype can have disjoint or overlapping entity subtypes. |
|
Definition
|
|
Term
| A total completeness constraint is represented by a _____. |
|
Definition
| double horizontal line under a circle |
|
|
Term
| According to the “preferably single-attribute” characteristic of a primary key, the primary key: |
|
Definition
| should have the minimum number of attributes possible. |
|
|
Term
|
Definition
|
|
Term
| To model time-variant data, one must create a new entity in an M:N relationship with the original entity. |
|
Definition
|
|
Term
| The purpose of an entity _____ is to simplify an entity-relationship diagram (ERD) and thus enhance its readability. |
|
Definition
|
|
Term
| In specialization hierarchies with multiple levels of supertype and subtypes, a lower-level subtype can inherit only a few of the attributes and relationships from its upper-level supertypes. |
|
Definition
|
|
Term
| The “_____” characteristic of a primary key states that the primary key should not have embedded semantic meaning. |
|
Definition
|
|
Term
| Which of the following is a specialization hierarchy overlapping constraint scenario in case of partial completeness? |
|
Definition
| Supertype has optional subtypes. |
|
|
Term
| Disjoint subtypes are subtypes that contain nonunique subsets of the supertype entity set. |
|
Definition
|
|
Term
| An entity cluster is formed by combining multiple interrelated entities into _____. |
|
Definition
| a single abstract entity object |
|
|
Term
| A(n) _____ is the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related. |
|
Definition
|
|
Term
| A _____ key is a real-world, generally accepted identifier used to uniquely identify real-world objects. |
|
Definition
|
|
Term
|
Definition
|
|
Term
| One important inheritance characteristic is that all entity subtypes inherit their primary key attribute from their supertype. |
|
Definition
|
|
Term
| The function of the primary key is to describe an entity. |
|
Definition
|
|
Term
| A design trap occurs when a relationship is improperly or incompletely identified and is therefore represented in a way that is not consistent with the real world. |
|
Definition
|
|
Term
| Which of the following is a specialization hierarchy overlapping constraint scenario in case of partial completeness? |
|
Definition
| Supertype has optional subtypes. |
|
|
Term
| The completeness constraint can be partial or total. |
|
Definition
|
|
Term
| The purpose of an entity _____ is to simplify an entity-relationship diagram (ERD) and thus enhance its readability. |
|
Definition
|
|
Term
| The _____ depicts the arrangement of higher-level entity supertypes (parent entities) and lower-level entity subtypes (child entities). |
|
Definition
|
|
Term
| An entity cluster is a "virtual" entity type used to represent multiple entities and relationships in the ERD. |
|
Definition
|
|
Term
| A(n)_____ is a generic entity type that is related to one or more entity subtypes. |
|
Definition
|
|
