a(n) ____ is the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related.
Given an example of its use. A subtype discriminator is the attribute in the supertype entity that is used to determine to which entity subtypethe supertype occurrence. is related. For any given supertype occurrence, the value of the subtype discriminatorwill determine which subtype the supertype occurrence is. 6 Disjoint and Overlapping Constraints • Disjoint subtypes – Also known as non-overlapping subtypes – Subtypes that contain unique subset of supertype entity set • Overlapping subtypes – Subtypes that contain nonunique subsets of supertype entity set Database Systems: Design. Implementation. & Management. Rob & Coronel 12 . The default comparison condition for the subtype discriminator attribute is the ____ comparison. a. not equality c. greater than b. less than d. equality ____ 32. Non-overlapping subtypes are subtypes that contain a(n) ____ subset of the supertype entity set. a. entity c. unique b. subtypes d. nonunique ____ 33. One important inheritance characteristic is that all entity subtypes inherit their ____ key attribute from their supertype. a. primary c. foreign b. natural d. surrogate ____ 29. In the specialization hierarchy there is a ____ relationship between a subtype and supertype. a. self-referring c. 1:M b. 1:1 d. M:N ____ 30. In the next section, you will learn how the entity supertypes and subtypes are related in a. specialization hierarchy. 6.1.2 Specialization Hierarchy. Entity supertypes and subtypes are organized in a specialization hierarchy, which depicts the arrangement of. A(n) ____ is the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related. a. subtype discriminator c. specialization hierarchy b. inheritance discriminator d. entity supertype ____ 31. Rob & Coronel 11 . 7th Edition. Implementation.6 Subtype Discriminator • The attribute in supertype entity that determines to which entity subtype each supertype occurrence is related • The default comparison condition for subtype discriminator attribute is equality comparison Database Systems: Design. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Subtype Discriminator. Attribute in the supertype entity that determines to. which entity subtype the supertype occurrence is. related. Default comparison condition is the equality. comparison. An entity supertype is a generic entity type that is related to one or more entity subtypes, where the entitysupertype contains the common. characteristics and the entity subtypes contain the unique characteristics of each entity subtype. 7th Edition. and clusters • Specialization hierarchy depicts arrangement and relationships between entity supertypes and entity subtypes • Inheritance allows an entity subtype to inherit attributes and relationships of supertype Database Systems: Design. Rob & Coronel 41 . Implementation. & Management.
Subtype discriminator