Database Models Comparison

Feature	Hierarchical Model	Network Model	Relational Model	Object-Oriented Model
Structure	Tree-like structure	Web-like structure (graph)	Tables with rows & columns	Objects with data & methods
Relationship	One-to-many (parent-child)	Many-to-many	Flexible, using keys	Complex relationships
Analogy	Family Tree 🌳	Spider’s Web 🕸️	Excel Spreadsheets 🧾	Real-world Objects 🚗
Key Advantage	Fast for specific queries	More flexible than Hierarchical	Very flexible & easy to use	Handles complex data well
Key Disadvantage	Very rigid, can’t do many-to-many	Can be very complex	Slower for some queries	Not widely used for business
Examples	File systems, IBM Information Management System (IMS)	Integrated Data Store (IDS), IDMS	MySQL, PostgreSQL, Oracle	GemStone, ObjectDB

Quick Notes:

Hierarchical and Network Models are older models focusing on rigid structures.
Relational Model is widely used and supports SQL.
Object-Oriented and Document Models are ideal for modern applications.
Graph and Time-Series Models are specialized for specific use cases like relationships and logs.

✅ DATABASE MODELS

🔶 SECTION A: BASIC CONCEPTS

1. A database model represents:

A. Hardware devices
B. Structure of data and relationships
C. Internet speed
D. Storage device only
Answer: B

2. A database model describes how data is:

A. Stored
B. Organized
C. Retrieved
D. All of the above
Answer: D

3. The most widely used database model today is:

A. Hierarchical
B. Network
C. Relational
D. Object-oriented
Answer: C

🔶 SECTION B: HIERARCHICAL MODEL

4. Hierarchical model organizes data in:

A. Graph
B. Tree structure
C. Table
D. Documents
Answer: B

5. In hierarchical model, the relationship is:

A. Many-to-many
B. One-to-many
C. One-to-one only
D. Many-to-one
Answer: B

6. Hierarchical model was used in:

A. IMS by IBM
B. Oracle
C. MySQL
D. MongoDB
Answer: A

7. Key disadvantage of hierarchical model:

A. Slow performance
B. No data integrity
C. Cannot handle many-to-many relationships
D. Low storage
Answer: C

8. Each child in a hierarchical model has:

A. Multiple parents
B. Only one parent
C. No parent
D. Random parents
Answer: B

🔶 SECTION C: NETWORK MODEL

9. Network model represents data using:

A. Graph structure
B. Table
C. Tree
D. Flat file
Answer: A

10. Network model supports:

A. Only one-to-one relationship
B. One-to-many & many-to-many
C. Only many-to-one
D. No relationships
Answer: B

11. The basic unit in network model is:

A. Table
B. Node and link
C. Object
D. File
Answer: B

12. The first network model standard was:

A. CODASYL
B. ER Model
C. Oracle Model
D. XML Model
Answer: A

🔶 SECTION D: RELATIONAL MODEL (Imp)

13. Relational model was introduced by:

A. Codd
B. Boyce
C. IBM
D. Merill Lynch
Answer: A

14. Relational model stores data in:

A. Files
B. Tables (Relations)
C. Trees
D. Nodes
Answer: B

15. In relational model, a row is called:

A. Attribute
B. Tuple
C. Domain
D. File
Answer: B

16. In relational model, a column is called:

A. Tuple
B. Attribute
C. Node
D. Entity
Answer: B

17. Keys (Primary, Foreign) belong to which model?

A. Hierarchical
B. Network
C. Relational
D. Flat-file
Answer: C

18. Relational model uses:

A. SQL
B. HTML
C. XML
D. Pascal
Answer: A

🔶 SECTION E: OBJECT-ORIENTED MODEL

19. Object-oriented model stores data as:

A. Objects
B. Files
C. Tables
D. Nodes
Answer: A

20. In object model, objects contain:

A. Data only
B. Functions only
C. Data + Methods
D. Keys only
Answer: C

21. Object model supports:

A. Inheritance
B. Polymorphism
C. Encapsulation
D. All of the above
Answer: D

🔶 SECTION F: OBJECT-RELATIONAL MODEL

22. Object-relational databases combine:

A. Network + Hierarchical
B. Object + Relational
C. XML + Table
D. File + Object
Answer: B

23. Object-relational databases are used in:

A. Oracle
B. PostgreSQL
C. Informix
D. All of these
Answer: D

🔶 SECTION G: ER (Entity–Relationship) MODEL

24. ER model was introduced by:

A. Codd
B. Chen
C. Bachman
D. Boyce
Answer: B

25. ER model uses:

A. Tables
B. Flowcharts
C. Entities and Relationships
D. Graph diagrams
Answer: C

26. In ER diagram, attribute is represented by:

A. Rectangle
B. Diamond
C. Ellipse
D. Arrow
Answer: C

27. Relationship in ER diagram is shown by:

A. Rectangle
B. Diamond
C. Triangle
D. Circle
Answer: B

28. Entity is represented by:

A. Rectangle
B. Ellipse
C. Diamond
D. Square
Answer: A

29. The primary key is represented by:

A. Underlined attribute
B. Bold attribute
C. Arrow
D. Circle
Answer: A

🔶 SECTION H: FLAT-FILE MODEL

30. Flat-file model stores data in:

A. Tables
B. CSV-like simple files
C. Graphs
D. Objects
Answer: B

31. Flat-file model has:

A. No relationships
B. No constraints
C. High redundancy
D. All of the above
Answer: D

🔶 SECTION I: SEMI-STRUCTURED & OTHER MODELS

32. XML model is:

A. Structured
B. Unstructured
C. Semi-structured
D. Graph-based
Answer: C

33. JSON model is commonly used in:

A. NoSQL databases
B. RDBMS
C. Excel
D. Mainframes
Answer: A

34. Graph database uses:

A. Nodes & Edges
B. Trees
C. Files
D. Tuples
Answer: A

35. Key example of graph database:

A. MongoDB
B. Neo4j
C. Oracle
D. MS Access
Answer: B

🔶 SECTION J: COMPARISON-BASED

36. Hierarchical vs Network Model — which supports multiple parents?

A. Hierarchical
B. Network
C. Both
D. None
Answer: B

37. Relational model was developed after:

A. Hierarchical & Network
B. ER Model
C. Object Model
D. XML Model
Answer: A

38. Which model is easiest to understand?

A. Hierarchical
B. Network
C. Relational
D. ER
Answer: D

39. Which model supports complex data types?

A. Relational
B. Object-Oriented
C. Hierarchical
D. Flat
Answer: B

40. Which model provides referential integrity?

A. Object
B. Relational
C. Network
D. Flat file
Answer: B

🔶 SECTION K:

41. A tuple represents:

A. Field
B. Row
C. Column
D. Domain
Answer: B

42. Domain represents:

A. Set of tables
B. Set of allowed values
C. Set of files
D. Set of databases
Answer: B

43. Many-to-many relationships are supported in:

A. Hierarchical
B. Network
C. Relational
D. Both B & C
Answer: D

44. 1:1 and 1:M cardinality belongs to:

A. Hierarchical
B. ER model
C. Network
D. Relational
Answer: B

🔶 SECTION L: REAL-LIFE BANKING

45. Customer–Account relationship in banking is:

A. One-to-one
B. One-to-many
C. Many-to-many
D. Recursive
Answer: B
(One customer → many accounts)

46. Account–Branch relationship is:

A. One-to-many
B. Many-to-one
C. Many-to-many
D. Both A and B
Answer: B

47. A loan involving multiple guarantors uses which model?

A. Hierarchical
B. Network (many-to-many)
C. Relational
D. Object
Answer: B

🔶 SECTION M: PAST YEAR & TRICKY QUESTIONS

48. The model using set theory and predicate logic is:

A. Hierarchical
B. Network
C. Relational
D. Object
Answer: C

49. ER model is a type of:

A. Conceptual model
B. Physical model
C. Combined model
D. None
Answer: A

50. Relational model considers each table as a:

A. File
B. Relation
C. Entity
D. Block
Answer: B

51. Which model is best for handling recursive relationships?

A. Hierarchical
B. Network
C. Object
D. XML
Answer: C

52. Which model is MOST used in banking systems?

A. Network
B. Relational
C. Flat-file
D. Object
Answer: B

🔶 SECTION N: ADVANCED/DIFFICULT

53. Object-relational model is also called:

A. Hybrid model
B. ER model
C. Semi-structured
D. Normalized model
Answer: A

54. Which model uses “parent-child” terminology?

A. Hierarchical
B. Relational
C. Object
D. Network
Answer: A

55. Many-to-one is supported by:

A. Only relational
B. Only network
C. Hierarchical
D. Object + Relational + Network
Answer: D

56. Which model is closest to real-world objects?

A. Network
B. Hierarchical
C. Relational
D. Object-oriented
Answer: D

🔶 SECTION O: TRUE OR FALSE

57. Hierarchical model uses a graph.

False
Correct: Uses a tree.

58. Relational model uses keys for relationships.

True

59. ER model is used for designing before implementation.

True

60. Object model cannot support inheritance.

False

🔶 SECTION P: MORE BONUS

(Important for exams)

61. In ER model, composite attribute is shown using:

A. Double ellipse
B. Dashed ellipse
C. Diamond
D. Square
Answer: A

62. Derived attribute is shown by:

A. Dotted ellipse
B. Double ellipse
C. Triangle
D. Arrow
Answer: A

63. Aggregation in ER model represents:

A. Weak entity
B. Relationship among relationships
C. Null values
D. Subclass
Answer: B – Aggregation is a process of combining data from multiple sources or entities to produce a single, meaningful summary or result

64. Weak entity depends on:

A. Strong entity
B. Another weak entity
C. User
D. Index
Answer: A

65. The relational model uses which normal forms?

A. 1NF
B. 2NF
C. 3NF
D. All of the above
Answer: D

66. Hierarchical model does NOT support:

A. Parent-child
B. Multiple parents
C. Top-down approach
D. One root
Answer: B

67. Network model solves what limitation of hierarchical model?

A. Lack of many-to-many relationships
B. Slow access
C. Top-down design
D. Storage issues
Answer: A

68. XML & JSON models are used in:

A. RDBMS
B. NoSQL
C. Flat-file
D. Object
Answer: B

69. Which model is easiest for conceptual design?

A. ER model
B. Relational
C. Network
D. Hierarchical
Answer: A

70. Star schema belongs to which data model?

A. Dimensional model
B. Hierarchical
C. Object
D. Network
Answer: A

71. Dimensional model is used in:

A. OLTP
B. OLAP
C. File system
D. Mobile apps
Answer: B

It is a way of organizing data for reports so that it becomes easy to understand and fast to analyze. Super Simple Example: Think of a shop’s sales data:

Fact = numbers you want to measure
Example: Total sales, quantity sold
Dimensions = details about those numbers
Example: Date, Product, Customer, Store

So, a Dimensional Model is like: One table with numbers (facts) + many tables with details (dimensions) to help you make reports quickly.

72. Relational model represents relationships using:

A. Columns
B. Foreign keys
C. Logs
D. Objects
Answer: B

73. Data redundancy is minimum in:

A. Hierarchical
B. Network
C. Relational
D. Flat-file
Answer: C

74. Data integrity is maximum in:

A. Flat-file
B. Network
C. Relational
D. Hierarchical
Answer: C

75. ER model helps in converting to:

A. Physical database
B. Logical schema
C. Conceptual + Logical
D. None
Answer: C

76. SQL is used in:

A. Hierarchical
B. Network
C. Relational
D. All
Answer: C

77. OODBMS stands for:

A. Object-Oriented DBMS
B. Oriented-Operational DB
C. Overlapped DB Model
D. Open-Object DB Manager
Answer: A

78. Graph model is best suited for:

A. Social networks
B. Banking
C. Insurance core
D. OLTP
Answer: A

79. Keys belong to which model?

A. Flat-file
B. Network
C. Relational
D. Object
Answer: C

80. Relational model uses:

A. Node-link
B. Table
C. Object
D. File
Answer: B