Data Management – Applications WGU EXAM TEST BANK WITH ALL VERSIONS OF THE EXAM WITH ALLMODULES COVERED | ACCURATE AND VERIFIED QUESTIONS AND ANSWERS FOR GUARANTEED PASS| LATEST UPDATE

1. In the relational model, _____ are important because they are used to ensure that each row in a table is uniquely identifiable. A. Tables B. Attributes C. Keys D. Records Correct Answer: C. Keys Rationale: Keys uniquely identify each row in a relational table, ensuring data integrity. 2. In a relational table, each column has a specific range of values known as the _____________. A. Attribute B. Key C. Index D. Domain Correct Answer: D. Domain Rationale: A domain defines the set of allowable values for a column (attribute). 3. The _____ relationship is the "relational model ideal." A. M:N B. 1:M C. 1:1 D. Recursive Correct Answer: B. 1:M Rationale: One-to-many (1:M) is ideal in relational databases for efficient data organization and access. 4. According to Codd's _____ rule of relational databases, "Application programs and ad hoc facilities are logically unaffected when changes are made to the table structures that preserve the original table values." A. Physical data independence B. Logical data independence C. Entity integrity D. Data consistency Correct Answer: B. Logical data independence Rationale: Logical data independence allows structural changes without affecting application logic. 5. The order of the rows and columns is important to the DBMS. (T/F) Correct Answer: False Rationale: In a relational model, the order of rows and columns does not affect data interpretation. 6. A(n) ____________ links tables on the basis of an equality condition that compares specified columns of each table. A. Outer join B. Equijoin C. Subquery D. Natural join Correct Answer: B. Equijoin Rationale: An equijoin links tables using equality conditions between columns. 7. When two or more tables share the same number of columns with compatible domains, they are said to be _____. A. Normalized B. Union-Compatible C. Primary-Related D. Attribute-Matched Correct Answer: B. Union-Compatible Rationale: Union-compatibility allows operations like UNION in relational algebra. 8. A table is also called a(n) _____________ in the relational model. A. Index B. Key C. Relation D. Join Correct Answer: C. Relation Rationale: In relational theory, a table is synonymous with a relation. 9. The __________ catalog describes all objects within the database, including table names, creation date, columns, data types, and access privileges. A. Reference B. Metadata C. System D. External Correct Answer: C. System Rationale: The system catalog stores metadata about the database. 10. The row's range of permissible values is known as its domain. (T/F) Correct Answer: False Rationale: Domain refers to the column (attribute), not the row. 11. The ___________ relationship is the relational database norm. A. 1:1 B. M:N C. 1:M D. Recursive Correct Answer: C. 1:M Rationale: 1:M relationships are the most common and natural form in relational databases. 12. To avoid nulls, some designers use special codes, known as ______, to indicate missing values. A. Pointers B. Tokens C. Flags D. Keys Correct Answer: C. Flags Rationale: Flags are special values used to represent missing or inapplicable data. 13. A data dictionary is sometimes described as "the database designer's database." (T/F) Correct Answer: True Rationale: A data dictionary stores metadata that helps designers manage database structure. 14. The SELECT operator yields a vertical subset of a table. (T/F) Correct Answer: False Rationale: SELECT yields a horizontal subset (rows); PROJECT yields a vertical subset (columns). 15. Character data can contain any character or symbol intended for mathematical manipulation. (T/F) Correct Answer: False Rationale: Character data is not meant for math manipulation; numeric data is. 16. _____ relationships can be implemented by creating a new entity in 1:M relationships with the original entities. A. 1:1 B. 1:M C. M:N D. Unary Correct Answer: C. M:N Rationale: M:N relationships are implemented using a bridge entity in 1:M relationships. 17. _________ is the real power behind relational databases, allowing the use of independent tables linked by attributes. A. Indexing B. Grouping C. Join D. Normalization Correct Answer: C. Join Rationale: Join operations combine related data from different tables. 18. A _____ is any key that uniquely identifies each row. A. Primary key B. Superkey C. Foreign key D. Candidate key Correct Answer: B. Superkey Rationale: A superkey is any combination of attributes that uniquely identifies rows. 19. One characteristic of generalization hierarchies is that they are implemented as ______ relationships. A. M:N B. 1:M C. 1:1 D. Recursive Correct Answer: C. 1:1 Rationale: Generalization hierarchies are often modeled as 1:1 relationships. 20. The _____ is a system-created database that stores user-created database metadata. A. Schema B. System catalog C. Data dictionary D. Metadata table Correct Answer: B. System catalog Rationale: The system catalog contains system-generated metadata. 21. Another name for a composite entity is a(n) _____ entity. A. Weak B. Strong C. Bridge D. Associative Correct Answer: C. Bridge Rationale: A bridge (or associative) entity links entities in M:N relationships. 22. If the CUSTOMER table's primary key column has no nulls and all unique entries, this is an example of _____ integrity. A. Referential B. Entity C. Domain D. Structural Correct Answer: B. Entity Rationale: Entity integrity requires primary key values to be unique and not null. 23. A(n) _____________ index has only one pointer (row) per key value. A. Composite B. Non-clustered C. Unique D. Hash Correct Answer: C. Unique Rationale: A unique index ensures that each value maps to a single row. 24. Proper data design requires controlled data redundancies to function properly. A. Normalization B. Warehousing C. Partitioning D. Denormalization Correct Answer: B. Warehousing Rationale: Data warehousing allows some redundancy for performance and reporting. 25. Dr. Codd's _____________ rule states every value is accessible via table name, PK, and column name. A. Guaranteed Access B. Entity Integrity C. System Independence D. Referential Rule Correct Answer: A. Guaranteed Access Rationale: This rule ensures full data accessibility in relational databases. 26. The DIVIDE operation uses a one-column table as divisor and two-column table as dividend. (T/F) Correct Answer: True Rationale: This relational algebra operation returns rows with all matching values. 27. In a database, the word _____ indicates using the same attribute name for different attributes. A. Alias B. Homonym C. Synonym D. Duplicate Correct Answer: B. Homonym Rationale: Homonyms are same-named but unrelated attributes, causing confusion. 28. The idea of determination is unique to databases. (T/F) Correct Answer: False Rationale: Determination is a broader logical concept, not exclusive to databases. 29. _____ are useful when identifying values in related tables causing referential integrity issues. A. Equijoins B. Subqueries C. Outer joins D. Views Correct Answer: C. Outer joins Rationale: Outer joins expose unmatched values, aiding integrity troubleshooting