DATA MODELING CONCEPT

Question 1

• High-level description of the data domain
• Does not constrain how that description is mapped to an actual implementation in software
• There may be many mappings

Answer 1

Conceptual Data Model

Question 2

• Being the scope of a model, it helps to describe the semantics of a domain

Answer 2

Conceptual Model

Question 3

• There are description of Tables, Columns, Object Oriented Classes, XML Tags, Document Structure

Answer 3

Logical Model

Question 4

• This Model Cares about the actual physical structure to store the data, like the partitions, CPU Spaces, Replications, Shards etc

Answer 4

Physical Model

Question 5

• Only addresses data and relationships. Classic, simplest. Best for deriving a sound table design. Many extensions/variations exist. Basis for most other modeling approaches

Answer 5

Entity-Relationship (E-R) Models

Question 6

• Class models. Goes beyond data, also models behaviors

Answer 6

UML (Unified Modeling Language)

Question 7

• Technology independent. Contains more detail than the Conceptual Data Model. Considered by many to be just an expanded conceptual data model

Answer 7

Logical Data Model

Question 8

• Documentation of the structure of the data. Used to communicate the design. Serve as the basis for data model implementation

Answer 8

Entity Relationship Model

Question 9

• effectively become tables

Answer 9

Entities

Question 10

• describe entities and become fields (columns) in tables

Answer 10

Attributes

Question 11

• link tables on a common attribute or “key” and become formal constraints (part of the business rules)

Answer 11

Relationships

Question 12

• maximum number of times an instance in one entity can be associated with instances in the related entity

Answer 12

Cardinality

Question 13

• minimum number of times an instance in one entity can be associated with instances in the related entity

Answer 13

Participation

Question 14

• Maximum number of times an instance of an entity can be associated with instances of a related entity
• Can ONLY have values of 1 or many
• Located closest to the entity in Crow’s Foot notation

Answer 14

Cardinality

Question 15

• Each row in a table should have an attribute that is a persistent, unique identifier

Answer 15

Primary Key

Question 15

Indicates whether an instance of an entity MUST participate in the relationship. Can ONLY have the values of 0 or 1

Answer 15

Participation

Question 16

• Tables represents both data and relationships. Multiple columns with unique names
• Each record type defines a fixed number of fields, or attributes
• Most widely used db

Answer 16

Relational Model

Question 17

• Collection of basic objects called entities and its relationships
• An entity is a real world thing or object
• Distinguishable from other objects
• Widely used in database design

Answer 17

ER Model

Question 18

• OOP Languages- C++, Java, C#, etc .Need for Object Oriented data model

Answer 18

Object-Based Model

Question 19

• Specification of data. Individual data items of the same type may have different sets of attributes. Using of 2 different language

Answer 19

Semistructured Data Model