Chapt.2 - Data Models

What is data model?

• Simple representations of complex real-world data structures

• Abstraction of a real-world object or event

• Process of creating a specific data model for a determined problem domain

• Clearly defined area within the real-world environment, with a well-defined scope and boundaries

Below are the reasons why the data model is important EXCEPT

• Help in visualizing data

• Provides a structure for data

• Organizes data for various users

• Increases the cost of data storage

• Are a communication tool

An implementation-ready data model should contain?

Hint: Please tick more than one answer

• A detailed description of the data structure

• A set of enforceable rules

• A data manipulation methodology

• The number of items of the model

Which are the basic building block(s) for the data model?

Hint: Please tick more than one answer

• Entity

• Relationship

• Cardinality

• Constraint

Written documentation is one of the source of Business Rules

• True
• False
• Not always
• Depends on the business

As a general rule, ___ in a business rule will translate into ___ in the model, and ___ that associates the nouns will translate into a ___ among the entities.

• nouns, entities, verb, relationship
• verbs, entities, noun, relationship
• nouns, verbs, relationship, entities
• entities, nouns, relationship, verbs

It is difficult to represent M:N relationships in this data model.

• Hierarchical data model
• Network data model
• Object-oriented data model

In the Relational Model, a tuple is represented as

• A row in a table
• A column in a table
• A table in a database

___ uses graphical representations to model database components.

What is the difference between a database schema and a database state?

• A database schema is the logical design of the database, while the database state refers to the data in the database at a particular moment in time.
• A database schema is the physical storage of the data, while the database state is the logical design of the database.
• A database schema is the data in the database, while the database state is the physical storage of the data.