D427 / D 427 Pre - Assessment V2 (Latest Update
) Data Management – Applications |
Questions and Answers | Grade A | 100% Correct
(Verified Answers) – WGU
Database Fundamentals and Concepts
1. What is the primary function of a relational database?
Answer: To store and manage data in tables with defined relationships
Rationale: Relational databases use tables linked by keys to ensure data integrity and
efficient querying.
2. What is a primary key in a database table?
Answer: A unique identifier for each row in a table
Rationale: Primary keys ensure each record is uniquely identifiable.
3. What is a foreign key?
Answer: A column that references a primary key in another table
Rationale: Foreign keys maintain referential integrity between tables.
4. What does the acronym SQL stand for?
Answer: Structured Query Language
Rationale: SQL is the standard language for managing relational databases.
5. What is the purpose of a database schema?
Answer: To define the structure and organization of the database
Rationale: A schema specifies tables, columns, data types, and relationships.
,6. What is a materialized view?
Answer: A stored query result that requires periodic refreshing
Rationale: Materialized views store data physically, unlike regular views.
7. Which two statements are true about a materialized view?
Answer: It is stored; It must be refreshed when the base table changes
Rationale: Materialized views are physically stored and need updates to reflect base
table changes.
8. What is a database management system (DBMS)?
Answer: Software for creating, managing, and querying databases
Rationale: DBMS (e.g., MySQL) facilitates data operations.
9. What is the purpose of normalization?
Answer: To eliminate data redundancy and ensure consistency
Rationale: Normalization organizes data into tables to meet normal forms.
10. What is the first normal form (1NF)?
Answer: Ensures atomic values and a unique identifier for each row
Rationale: 1NF eliminates repeating groups and requires a primary key.
11. What is a composite key?
Answer: A primary key composed of two or more columns
Rationale: Composite keys uniquely identify rows when a single column is insufficient.
12. What is referential integrity?
Answer: Ensuring foreign key values match existing primary key values
Rationale: This maintains consistency between related tables.
13. What is a strong entity in ER modeling?
Answer: An entity with a unique identifying attribute
Rationale: Strong entities do not depend on other entities for identification.
, 14. What is a many-to-many relationship?
Answer: Multiple records in one table relate to multiple records in another
Rationale: This requires a junction table to resolve.
15. What is an example of a one-to-one relationship?
Answer: A salesperson and an office space/cubicle
Rationale: Each salesperson is assigned one cubicle, and vice versa.
16. What is the purpose of an entity-relationship diagram (ERD)?
Answer: To visually represent entities and their relationships
Rationale: ERDs aid in designing and understanding database structures.
17. What symbol represents a one-to-many relationship in an ERD?
Answer: A crow’s foot
Rationale: The crow’s foot notation indicates multiple records on one side.
18. What is a heap table?
Answer: A table with no specific order imposed on rows
Rationale: Heap tables store data without a predefined order.
19. What data type stores fractional numbers?
Answer: DECIMAL
Rationale: DECIMAL allows precise storage of numbers with decimal points.
20. What is the syntax for the DATETIME data type?
Answer: YYYY-MM-DD HH:MM:SS
Rationale: DATETIME stores both date and time components.
SQL Data Definition Language (DDL)
) Data Management – Applications |
Questions and Answers | Grade A | 100% Correct
(Verified Answers) – WGU
Database Fundamentals and Concepts
1. What is the primary function of a relational database?
Answer: To store and manage data in tables with defined relationships
Rationale: Relational databases use tables linked by keys to ensure data integrity and
efficient querying.
2. What is a primary key in a database table?
Answer: A unique identifier for each row in a table
Rationale: Primary keys ensure each record is uniquely identifiable.
3. What is a foreign key?
Answer: A column that references a primary key in another table
Rationale: Foreign keys maintain referential integrity between tables.
4. What does the acronym SQL stand for?
Answer: Structured Query Language
Rationale: SQL is the standard language for managing relational databases.
5. What is the purpose of a database schema?
Answer: To define the structure and organization of the database
Rationale: A schema specifies tables, columns, data types, and relationships.
,6. What is a materialized view?
Answer: A stored query result that requires periodic refreshing
Rationale: Materialized views store data physically, unlike regular views.
7. Which two statements are true about a materialized view?
Answer: It is stored; It must be refreshed when the base table changes
Rationale: Materialized views are physically stored and need updates to reflect base
table changes.
8. What is a database management system (DBMS)?
Answer: Software for creating, managing, and querying databases
Rationale: DBMS (e.g., MySQL) facilitates data operations.
9. What is the purpose of normalization?
Answer: To eliminate data redundancy and ensure consistency
Rationale: Normalization organizes data into tables to meet normal forms.
10. What is the first normal form (1NF)?
Answer: Ensures atomic values and a unique identifier for each row
Rationale: 1NF eliminates repeating groups and requires a primary key.
11. What is a composite key?
Answer: A primary key composed of two or more columns
Rationale: Composite keys uniquely identify rows when a single column is insufficient.
12. What is referential integrity?
Answer: Ensuring foreign key values match existing primary key values
Rationale: This maintains consistency between related tables.
13. What is a strong entity in ER modeling?
Answer: An entity with a unique identifying attribute
Rationale: Strong entities do not depend on other entities for identification.
, 14. What is a many-to-many relationship?
Answer: Multiple records in one table relate to multiple records in another
Rationale: This requires a junction table to resolve.
15. What is an example of a one-to-one relationship?
Answer: A salesperson and an office space/cubicle
Rationale: Each salesperson is assigned one cubicle, and vice versa.
16. What is the purpose of an entity-relationship diagram (ERD)?
Answer: To visually represent entities and their relationships
Rationale: ERDs aid in designing and understanding database structures.
17. What symbol represents a one-to-many relationship in an ERD?
Answer: A crow’s foot
Rationale: The crow’s foot notation indicates multiple records on one side.
18. What is a heap table?
Answer: A table with no specific order imposed on rows
Rationale: Heap tables store data without a predefined order.
19. What data type stores fractional numbers?
Answer: DECIMAL
Rationale: DECIMAL allows precise storage of numbers with decimal points.
20. What is the syntax for the DATETIME data type?
Answer: YYYY-MM-DD HH:MM:SS
Rationale: DATETIME stores both date and time components.
SQL Data Definition Language (DDL)
