Schemas And Data Modelling in Power BI

Source: Dev.to

Introduction

Data Modelling in Power BI

Fact Table

Dimension Table

Relationships in Power BI

Types of Relationships

• One-to-Many (1:*) – One record in a dimension table relates to many records in a fact table.
  Example: one customer (dimension) can have many sales transactions (fact).
• Many-to-One (*:1) – The reverse of one-to-many; many records in a fact table connect to a single record in a dimension table.
• Many-to-Many (:*) – Multiple records in one table relate to multiple records in another. Power BI can handle these, but they are more complex and should be used carefully.

Star Schema

Advantages of Star Schemas

• Simple design
• Easy to understand
• Provides better performance during data analysis

Snowflake Schema

Advantages of Snowflake Schema

• Reduced data redundancy
• Improved data integrity

Importance of Good Data Modelling

Conclusion

Schemas and data modelling are essential for effective Power BI reporting. Understanding how fact and dimension tables work, setting up the right relationships, and choosing an appropriate schema help reports run efficiently and deliver accurate insights. Applying good data modelling practices ensures reliable reporting, faster performance, and better decision‑making.