Star schema concept in Power BI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a star schema in Business Intelligence?

A star schema is a simple database design that organizes data into one central fact table connected to multiple dimension tables, like points of a star.

beginner

What is the role of the fact table in a star schema?

The fact table stores measurable, numeric data like sales or quantities, and keys that link to dimension tables.

beginner

Name three common dimension tables in a star schema for sales data.

Common dimension tables include Date (time), Product, and Customer.

beginner

Why is the star schema easy to understand and use?

Because it has a clear, simple structure with one fact table in the center and related dimension tables around it, making queries straightforward.

intermediate

How does a star schema improve report performance in Power BI?

It reduces complex joins by having simple relationships, which helps Power BI process queries faster and makes reports more responsive.

In a star schema, what type of data is stored in the fact table?

A Only text data

B Numeric measures and keys

C Descriptions and categories

D Unrelated data

The fact table holds numeric measures like sales amounts and keys linking to dimension tables.

Which of these is NOT a typical dimension table in a star schema?

A Sales Amount

B Product

C Date

D Customer

Sales Amount is a measure stored in the fact table, not a dimension table.

What shape does the star schema resemble?

A Star

B Circle

C Triangle

D Square

The schema looks like a star with a central fact table and dimension tables around it.

Why do star schemas help improve query speed in Power BI?

A Because they store data in one big table

B Because they use many complex joins

C Because they have a simple, clear structure

D Because they avoid using keys

The simple structure reduces complex joins, making queries faster.

Which table in a star schema contains foreign keys to dimension tables?

A Reference table

B Dimension table

C Lookup table

D Fact table

The fact table contains foreign keys linking to each dimension table.

Explain the structure of a star schema and why it is useful in Power BI.

Think about how a star looks and how data is organized around a central point.

Describe the difference between fact tables and dimension tables in a star schema.

Consider what kind of data each table stores and their roles.