How Data Modelling, Schemas, and Joins Shape Effective Power BI Reports

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Data modelling in Power BI involves organizing tables, keys, and relationships to enable accurate and efficient analysis. Designers typically choose between flat-table, star schema, and snowflake schema approaches, with the star schema being the most widely recommended for its performance and clarity. Fact tables store measurable business events while dimension tables hold descriptive attributes, and the two are linked through primary and foreign key relationships. Relationships in Power BI keep tables logically separate and allow filters to flow across them, whereas Power Query merges physically combine data during preparation. For most projects, a star schema with one-to-many relationships and single-direction filtering is considered the most reliable and maintainable foundation.

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