ISDS 402 FINAL TEST QUESTIONS
ANSWERS PRACTICE SCRIPT 2026
QUESTIONS WITH ANSWERS GRADED A+
>> EERM (Extended ER Model)
Answer: ER model with additional semantic constructs like supertypes/subtypes and specialization.
>> EERD
Answer: A diagram that uses the Extended ER Model constructs.
>> Entity Supertype
Answer: Generic entity with common attributes for one or more subtypes.
>> Entity Subtype
Answer: Specialized entity with attributes unique to that subtype.
>> Subtype Discriminator
Answer: Supertype attribute that determines a row's subtype membership.
>> Disjoint Subtypes
Answer: Nonoverlapping subtypes; each supertype instance belongs to at most one subtype.
>> Overlapping Subtypes
Answer: A supertype instance may belong to multiple subtypes.
>> Partial Completeness
Answer: Not every supertype instance must be a subtype member.
>> Total Completeness
Answer: Every supertype instance must be in at least one subtype.
>> Specialization
Answer: Top-down: identify subtypes from a supertype.
>> Generalization
Answer: Bottom-up: identify a supertype from subtypes.
>> Attribute Inheritance
Answer: Subtypes inherit supertype attributes and relationships.
, >> Entity Cluster
Answer: Virtual entity representing multiple related entities in one ERD object.
>> Primary Key
Answer: Attribute(s) that uniquely identify each row; enforces entity integrity.
>> Natural Key
Answer: Real-world, business-defined identifier (e.g., SSN, VIN).
>> Surrogate Key
Answer: System-generated key with no business meaning.
>> Composite Key
Answer: Primary key consisting of two or more attributes.
>> Weak Entity
Answer: Entity whose existence depends on another entity; often uses composite PK.
>> Fan Trap
Answer: Design trap when one entity is in two 1:M relationships causing unintended associations.
>> Redundant Relationship
Answer: Multiple paths between related entities; must be kept consistent.
>> Time-Variant Data
Answer: Data whose values change over time; history must be retained.
>> History Table Pattern
Answer: Add a 1:M child entity with value and effective dates to keep history.
>> Foreign Key Placement (1:1)
Answer: Place FK on dependent/optional side; sometimes either side if truly 1:1.
>> Participation Constraint
Answer: Defines whether participation is mandatory or optional.
>> Connectivity/Cardinality
Answer: Quantifies relationship pairs (1:1, 1:M, M:N).
>> Business Rule
Answer: Statement defining or constraining aspects of the business; drives data model.
ANSWERS PRACTICE SCRIPT 2026
QUESTIONS WITH ANSWERS GRADED A+
>> EERM (Extended ER Model)
Answer: ER model with additional semantic constructs like supertypes/subtypes and specialization.
>> EERD
Answer: A diagram that uses the Extended ER Model constructs.
>> Entity Supertype
Answer: Generic entity with common attributes for one or more subtypes.
>> Entity Subtype
Answer: Specialized entity with attributes unique to that subtype.
>> Subtype Discriminator
Answer: Supertype attribute that determines a row's subtype membership.
>> Disjoint Subtypes
Answer: Nonoverlapping subtypes; each supertype instance belongs to at most one subtype.
>> Overlapping Subtypes
Answer: A supertype instance may belong to multiple subtypes.
>> Partial Completeness
Answer: Not every supertype instance must be a subtype member.
>> Total Completeness
Answer: Every supertype instance must be in at least one subtype.
>> Specialization
Answer: Top-down: identify subtypes from a supertype.
>> Generalization
Answer: Bottom-up: identify a supertype from subtypes.
>> Attribute Inheritance
Answer: Subtypes inherit supertype attributes and relationships.
, >> Entity Cluster
Answer: Virtual entity representing multiple related entities in one ERD object.
>> Primary Key
Answer: Attribute(s) that uniquely identify each row; enforces entity integrity.
>> Natural Key
Answer: Real-world, business-defined identifier (e.g., SSN, VIN).
>> Surrogate Key
Answer: System-generated key with no business meaning.
>> Composite Key
Answer: Primary key consisting of two or more attributes.
>> Weak Entity
Answer: Entity whose existence depends on another entity; often uses composite PK.
>> Fan Trap
Answer: Design trap when one entity is in two 1:M relationships causing unintended associations.
>> Redundant Relationship
Answer: Multiple paths between related entities; must be kept consistent.
>> Time-Variant Data
Answer: Data whose values change over time; history must be retained.
>> History Table Pattern
Answer: Add a 1:M child entity with value and effective dates to keep history.
>> Foreign Key Placement (1:1)
Answer: Place FK on dependent/optional side; sometimes either side if truly 1:1.
>> Participation Constraint
Answer: Defines whether participation is mandatory or optional.
>> Connectivity/Cardinality
Answer: Quantifies relationship pairs (1:1, 1:M, M:N).
>> Business Rule
Answer: Statement defining or constraining aspects of the business; drives data model.
