Understanding Data Models

What is a relational data model?

• A relational data model uses graphs to represent data relationships.

• A relational data model is a way to structure data using tables that represent entities and their relationships.

• A relational data model is a method for storing data in a single file.

• A relational data model is a programming language for database management.

Name three key components of a relational data model.

• Columns, Keys, Views

• Tables, Attributes, Relationships

• Entities, Attributes, Indexes

• Records, Fields, Constraints

What is the purpose of primary keys in a relational database?

• The purpose of primary keys in a relational database is to uniquely identify each record in a table.

• To group related records together in a table.

• To define the data types of each column in a table.

• To store large amounts of data efficiently.

Explain the concept of normalization in data modeling.

• Normalization is the process of structuring a relational database to minimize redundancy and dependency by organizing fields and tables.

• Normalization is the technique of encrypting data for security purposes.

• Normalization is the process of increasing redundancy in a database.

• Normalization refers to the method of combining multiple databases into one.

What are the benefits of using a relational data model?

• Unstructured data storage

• Benefits of using a relational data model include data integrity, reduced redundancy, structured data organization, and powerful querying capabilities with SQL.

• Limited data access

• Increased data duplication

Describe the difference between a one-to-one and a one-to-many relationship.

• In a one-to-one relationship, entities can exist independently; in a one-to-many relationship, entities are always dependent on each other.

• In a one-to-one relationship, each entity is paired with one other entity; in a one-to-many relationship, one entity can be paired with multiple entities.

• In a one-to-one relationship, one entity can be paired with multiple entities; in a one-to-many relationship, each entity is paired with one other entity.

• A one-to-one relationship allows multiple entities to be paired with one entity, while a one-to-many relationship restricts it to one entity only.

What is an entity-relationship diagram (ERD)?

• A graphical representation of SQL queries.

• An entity-relationship diagram (ERD) is a diagram that shows the relationships between entities in a database.

• A diagram that only shows the data types of entities.

• A flowchart that outlines the steps in a database process.

List two design principles for effective data modeling.

• Ignoring data types in relationships;

• 1. Normalization to reduce redundancy; 2. Clear relationships between entities.

• Using only one entity for all data;

• Prioritizing aesthetics over functionality.

What is data redundancy and why is it a concern in data models?

• Data redundancy is the elimination of duplicate data to improve efficiency.

• Data redundancy is the backup of data to prevent loss.

• Data redundancy is the process of compressing data to save space.

• Data redundancy is the unnecessary duplication of data, and it is a concern because it can lead to inconsistencies and increased storage costs.

How does data integrity relate to data model design?

• Data model design focuses solely on aesthetics, not data accuracy.

• Data integrity is essential in data model design as it enforces rules and constraints that maintain the accuracy and consistency of data.

• Data integrity only applies to data storage, not to model design.

• Data integrity is irrelevant to data model design.