3 Building a Star Schema Data Model

Question 1

What is the purpose of data relationships in Power BI?

Answer 1

To connect related data in different tables to enable meaningful analysis and reporting.

Question 2

List the benefits of proper relationship management in Power BI.

Answer 2

• Data Integrity
• Improved Query Performance
• Enhanced Data Exploration
• Interactive Analysis

Question 3

Define the Star Schema model.

Answer 3

A data model characterized by a central fact table and dimension tables.

Question 4

What does the central fact table in a Star Schema contain?

Answer 4

Quantitative data and foreign keys to dimension tables.

Question 5

What do dimension tables in a Star Schema contain?

Answer 5

Descriptive attributes and primary keys.

Question 6

What is a key advantage of using a Star Schema?

Answer 6

Simplified and faster queries compared to more normalized models.

Question 7

What is meant by ‘grain’ in a fact table?

Answer 7

The level of detail in a fact table (e.g., daily sales, individual orders).

Question 8

What are additive measures in a fact table?

Answer 8

Values that can be summed or averaged.

Question 9

Explain the concept of hierarchies in dimension tables.

Answer 9

Hierarchies represent levels of data organization (e.g., City -> State -> Country).

Question 10

What are slowly changing dimensions?

Answer 10

Dimensions that handle changes in attributes over time.

Question 11

What is the significance of the autodetect feature in Power BI?

Answer 11

It automatically detects relationships between tables but has limitations.

Question 12

What type of relationship requires a bridge table in Power BI?

Answer 12

Many-to-many relationships.

Question 13

How does cross filter direction impact filtering in reports?

Answer 13

It affects how filters are applied based on the direction set.

Question 14

What are some data modeling best practices?

Answer 14

• Use a star schema
• Ensure data consistency
• Use descriptive column names

Question 15

Fill in the blank: The central fact table in a Star Schema model contains ______.

Answer 15

[quantitative data and foreign keys to dimension tables]

Question 16

True or False: Dimension tables in a Star Schema contain quantitative data.

Answer 16

False

Question 17

What are the benefits of using a Star Schema in data modeling?

Answer 17

• Ease of Understanding
• Improved Performance
• Business User Friendly

Question 18

What is the impact of bidirectional filtering on performance?

Answer 18

It can negatively impact performance.