Power BI Data Modeling & DAX Questions

Understand Power BI's data modeling concepts: relationships (one-to-many, many-to-many), cardinality, filter propagation, and bidirectional relationships. Write DAX formulas for measures and calculated columns, including basic (SUM, COUNT, AVERAGE) and advanced functions (CALCULATE, FILTER, ALL, VALUES). Understand variables and performance implications of DAX formulas.

EasyTechnical

59 practiced

Describe the purpose of USERELATIONSHIP in DAX. You have Sales(OrderDate, ShipDate, OrderID) and Calendar(Date). Without changing model relationships, explain how you would write a DAX measure to compute total sales by ShipDate using an inactive relationship and USERELATIONSHIP.

HardTechnical

65 practiced

Explain how the VertiPaq engine compresses columnar data in Power BI. For a model with many wide textual columns and high-cardinality fields, list concrete steps to reduce memory footprint including data type changes, dictionary encoding considerations, and ETL strategies.

EasyTechnical

72 practiced

When should you use RELATED versus LOOKUPVALUE in a Power BI model? Given tables Orders(order_id:int, customer_id:int) and Customers(customer_id:int, customer_name:string), explain how to return customer_name in Orders as a calculated column and when it is preferable to use LOOKUPVALUE instead of RELATED.

EasyTechnical

73 practiced

Explain filter propagation and cross-filter direction in Power BI models. Describe differences between single-direction and bidirectional relationships, how filters flow across chains of tables, and potential pitfalls of using bidirectional filtering.

MediumSystem Design

67 practiced

You must allow users to slice reports by either Order Date or Ship Date simultaneously while preserving correct measures. Propose a data model and DAX pattern that supports both slicers without duplicating measures, mentioning disconnected slicers, USERELATIONSHIP, SWITCH logic, or TREATAS where appropriate.

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