Database Fundamentals

Question 1

1. Main difference between primary key and foreign key? (Options: Foreign keys faster; Primary more important; PK can be NULL; PK uniquely identify records, FK reference PKs)

Answer 1

Primary keys uniquely identify records in their own table; foreign keys reference primary keys in other tables

Question 2

2. Correct schema development order? (Options: Physical→Conceptual→Logical; Physical→Logical→Conceptual; Conceptual→Logical→Physical; Logical→Conceptual→Physical)

Answer 2

Conceptual → Logical → Physical

Question 3

3. Cardinality represents? (Options: Numerical relationship; Size; Data type; Speed)

Answer 3

Numerical relationship between entities

Question 4

4. Students & Courses relationship? (Options: None; One-to-many; Many-to-many; One-to-one)

Answer 4

Many-to-many

Question 5

5. How many primary keys per table? (Options: Unlimited; Zero; Two; One)

Answer 5

One

Question 6

6. Social media relational limitation? (Options: Rigid schema; Lack security; Cannot create relationships; Poor support)

Answer 6

Rigid schema and unstructured data handling

Question 7

7. Relationship needing junction table? (Options: Many-to-many; One-to-one; All; One-to-many)

Answer 7

Many-to-many

Question 8

8. Eliminates transitive dependencies? (Options: 2NF; Cannot eliminate; 3NF; 1NF)

Answer 8

Third Normal Form (3NF)

Question 9

9. Overall logical structure without implementation? (Options: Physical; Implementation; Logical; Conceptual)

Answer 9

Conceptual schema

Question 10

10. PublisherID in Books table? (Options: Primary; Candidate; Foreign; Composite)

Answer 10

Foreign key

Question 11

11. Diamond in ERD represents? (Options: Attribute; Entity; Relationship; Primary key)

Answer 11

Relationship

Question 12

12. Attribute is? (Options: Relationship; Key; Table; Characteristic/property)

Answer 12

Characteristic or property of an entity

Question 13

13. Email data type? (Options: BOOLEAN; DATE; INT; VARCHAR)

Answer 13

VARCHAR

Question 14

14. Partial-key dependency? (Options: No PK; Missing FK; Non-key depends on part of composite PK; Incomplete PK)

Answer 14

Non-key attribute depends on part of a composite primary key

Question 15

15. Entity? (Options: Distinct object; Query; Column; Relationship)

Answer 15

Distinct object or concept about which data is stored

Question 16

16. Concatenated key similar to? (Options: Composite; Foreign; Candidate; Primary)

Answer 16

Composite key

Question 17

17. Denormalization? (Options: Always error; Intentional redundancy; Remove normal forms; No use)

Answer 17

Intentionally introducing redundancy to improve query performance

Question 18

18. Multiple values in one cell violates? (Options: Atomicity 1NF; Integrity; Referential integrity; Functional dependency)

Answer 18

Atomicity (1NF)

Question 19

19. Relational DB limitation? (Options: Unstructured data difficulty; Cannot create relationships; No security; Cannot store structured)

Answer 19

Difficulty handling unstructured data with unpredictable formats

Question 20

20. Best primary key in Students? (Options: Name; StudentID; GradeLevel; Email)

Answer 20

StudentID

Question 21

21. Eliminates partial-key dependencies? (Options: 2NF; 1NF; 3NF; Cannot eliminate)

Answer 21

Second Normal Form (2NF)

Question 22

22. VARCHAR vs TEXT? (Options: VARCHAR max length; TEXT faster; No difference; VARCHAR numbers only)

Answer 22

VARCHAR has a specified maximum length; TEXT does not have strict length limits

Question 23

23. Atomic values required by? (Options: 4NF; 3NF; 1NF; 2NF)

Answer 23

First Normal Form (1NF)

Question 24

24. Country–Capital relationship? (Options: Many-to-many; One-to-one; None; One-to-many)

Answer 24

One-to-one

Question 25

25. B-tree index & SSD specified in? (Options: Physical; Logical; Conceptual; Abstract)

Answer 25

Physical schema

Question 26

26. Reduced redundancy means? (Options: Fewer users; Less security; Multiple backups; Minimize repetition)

Answer 26

Minimizing unnecessary repetition of data

Question 27

27. Student–ID card relationship? (Options: One-to-one; Many-to-one; Many-to-many; One-to-many)

Answer 27

One-to-one

Question 28

28. Teacher teaches multiple courses? (Options: Many-to-one; One-to-one; One-to-many; Many-to-many)

Answer 28

One-to-many

Question 29

29. Modality indicates? (Options: Data type; # tables; Required/optional; Speed)

Answer 29

Whether a relationship is required (mandatory) or optional

Question 30

30. Data type for $19.99? (Options: BOOLEAN; VARCHAR; DECIMAL; INT)

Answer 30

DECIMAL

Question 31

31. Graduated yes/no data type? (Options: BOOLEAN; VARCHAR; DATE; INT)

Answer 31

BOOLEAN

Question 32

32. Age data type? (Options: INT; BOOLEAN; VARCHAR; TEXT)

Answer 32

INT

Question 33

33. NOT valid primary key? (Options: GradeLevel; ISBN; Email unique; StudentID)

Answer 33

GradeLevel

Question 34

34. Foreign key definition? (Options: References PK; Second important; Rarely used; From another DB)

Answer 34

A column that references the primary key of another table

Question 35

35. One-to-many FK placement? (Options: Junction; Customers; Orders; Both)

Answer 35

In the Orders table

Question 36

36. Ovals in ERD? (Options: Entities; Relationships; Tables; Attributes)

Answer 36

Attributes

Question 37

37. Authors & Books structure? (Options: Authors only; Authors, Books, Junction; Authors & Books; Books only)

Answer 37

Authors, Books, and AuthorBooks junction table

Question 38

38. StudentID→Zip→City dependency? (Options: Partial-key; Transitive; None; Direct)

Answer 38

Transitive dependency

Question 39

39. Multiple users without conflict benefit? (Options: Concurrency control; Scalability; Support; Integrity)

Answer 39

Concurrency control

Question 40

40. Transitive dependency occurs when? (Options: Non-key depends on non-key; Too many columns; PK depends on FK; FK depends on PK)

Answer 40

A non-key attribute depends on another non-key attribute

Question 41

41. Logical schema excludes? (Options: Storage locations/indexes; Relationships; Column names/types; Table names)

Answer 41

Specific storage locations and DBMS-specific indexes

Question 42

42. TRUE about primary keys? (Options: Duplicates allowed; NULL allowed; Must uniquely identify; Multiple PKs allowed)

Answer 42

Primary keys must uniquely identify each record

Question 43

43. FlightNumber + Date key? (Options: Composite; Primary; Secondary; Foreign)

Answer 43

Composite key

Question 44

44. Valid prescription references demonstrate? (Options: Scalability; Integrity; Support; Reduced redundancy)

Answer 44

Data integrity

Question 45

45. Goal of normalization? (Options: Eliminate relationships; Reduce redundancy & improve integrity; Slower queries; Increase redundancy)

Answer 45

To reduce data redundancy and improve integrity

Question 46

46. Denormalization appropriate when? (Options: Frequent updates; Banking system; Never; Read-intensive analytics)

Answer 46

In a read-intensive analytics system with complex multi-table joins

Question 47

47. Purpose of Enrollments table? (Options: Demographics; Replace Students; Course descriptions; Create M:M relationship)

Answer 47

To create a many-to-many relationship between Students and Courses

Question 48

48. Primary purpose of primary key? (Options: Uniquely identify record; Store important data; Create relationships; Sort alphabetically)

Answer 48

To uniquely identify each record in the table

Question 49

49. Purpose of ERD? (Options: Visualize entities; Look professional; Slow development; Not useful)

Answer 49

To visualize entities, attributes, and relationships before implementation

Question 50

50. Entity symbol in ERD? (Options: Triangle; Rectangle; Diamond; Circle/Oval)

Answer 50

Rectangle