ISDS 402 FINAL TEST QUESTIONS
ANSWERS STUDY GUIDE COMPLETE 2026
QUESTIONS WITH SOLUTIONS GRADED
A+
>> Subtype
Answer: A subset of entities in a supertype that share unique attributes.
>> Supertype
Answer: A generic entity type related to one or more subtypes.
>> Specialization Hierarchy
Answer: A hierarchy where a supertype is divided into subtypes.
>> Disjoint Subtypes
Answer: Subtypes that do not share membership; an instance belongs to only one subtype.
>> Overlapping Subtypes
Answer: Subtypes where an instance can belong to multiple subtypes.
>> Subtype Discriminator
Answer: An attribute in the supertype that determines the subtype.
>> Entity Cluster
Answer: A virtual entity made up of multiple related entities.
>> Inheritance
Answer: Subtypes inherit attributes and relationships of the supertype.
>> Normalization
Answer: The process of organizing data to reduce redundancy.
>> 1NF (First Normal Form)
Answer: No repeating groups, all attributes are atomic.
>> 2NF (Second Normal Form)
Answer: 1NF + no partial dependencies.
>> 3NF (Third Normal Form)
, Answer: 2NF + no transitive dependencies.
>> BCNF (Boyce-Codd Normal Form)
Answer: 3NF + every determinant is a candidate key.
>> Denormalization
Answer: Purposefully introducing redundancy for performance.
>> Surrogate Key
Answer: A system-assigned unique identifier.
>> DDL (Data Definition Language)
Answer: Commands like CREATE, ALTER, DROP.
>> DML (Data Manipulation Language)
Answer: Commands like INSERT, UPDATE, DELETE.
>> SELECT
Answer: Used to query the database.
>> JOIN
Answer: Combines rows from multiple tables based on related columns.
>> Aggregate Functions
Answer: SUM, AVG, COUNT, etc.
>> Subquery
Answer: A nested query within a query.
>> Set Operators
Answer: UNION, INTERSECT, MINUS.
>> CREATE TABLE
Answer: Defines a new table.
>> CONSTRAINTS
Answer: Rules enforced on data (e.g., PRIMARY KEY, FOREIGN KEY, CHECK).
>> ALTER TABLE
Answer: Modifies an existing table.
ANSWERS STUDY GUIDE COMPLETE 2026
QUESTIONS WITH SOLUTIONS GRADED
A+
>> Subtype
Answer: A subset of entities in a supertype that share unique attributes.
>> Supertype
Answer: A generic entity type related to one or more subtypes.
>> Specialization Hierarchy
Answer: A hierarchy where a supertype is divided into subtypes.
>> Disjoint Subtypes
Answer: Subtypes that do not share membership; an instance belongs to only one subtype.
>> Overlapping Subtypes
Answer: Subtypes where an instance can belong to multiple subtypes.
>> Subtype Discriminator
Answer: An attribute in the supertype that determines the subtype.
>> Entity Cluster
Answer: A virtual entity made up of multiple related entities.
>> Inheritance
Answer: Subtypes inherit attributes and relationships of the supertype.
>> Normalization
Answer: The process of organizing data to reduce redundancy.
>> 1NF (First Normal Form)
Answer: No repeating groups, all attributes are atomic.
>> 2NF (Second Normal Form)
Answer: 1NF + no partial dependencies.
>> 3NF (Third Normal Form)
, Answer: 2NF + no transitive dependencies.
>> BCNF (Boyce-Codd Normal Form)
Answer: 3NF + every determinant is a candidate key.
>> Denormalization
Answer: Purposefully introducing redundancy for performance.
>> Surrogate Key
Answer: A system-assigned unique identifier.
>> DDL (Data Definition Language)
Answer: Commands like CREATE, ALTER, DROP.
>> DML (Data Manipulation Language)
Answer: Commands like INSERT, UPDATE, DELETE.
>> SELECT
Answer: Used to query the database.
>> JOIN
Answer: Combines rows from multiple tables based on related columns.
>> Aggregate Functions
Answer: SUM, AVG, COUNT, etc.
>> Subquery
Answer: A nested query within a query.
>> Set Operators
Answer: UNION, INTERSECT, MINUS.
>> CREATE TABLE
Answer: Defines a new table.
>> CONSTRAINTS
Answer: Rules enforced on data (e.g., PRIMARY KEY, FOREIGN KEY, CHECK).
>> ALTER TABLE
Answer: Modifies an existing table.
