Power BI 778 Cheat Sheet 2026

The 30 highest-yield Power BI 778 facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is the Power BI REST API used for? → Programmatically managing Power BI resources like workspaces, datasets, and reports
2. In DAX Studio's Server Timings pane, what does a disproportionately high Formula Engine (FE) time relative to Storage Engine (SE) time typically indicate? → The DAX contains complex iterating logic the storage engine cannot fully handle
3. Which Power BI storage mode loads all data into the in-memory VertiPaq engine for the fastest query performance? → Import
4. What is required to enable Scheduled Refresh for an on-premises data source in Power BI? → An on-premises data gateway
5. What are the three workspace roles in Power BI Service? → Admin, Member, Contributor, Viewer
6. What does the EARLIER function do in DAX? → References an outer row context in a nested row context iteration
7. What is the dataset size limit per dataset in a Power BI Pro workspace when using Import mode? → 1 GB
8. What is a common performance drawback of excessive bidirectional cross-filtering in a Power BI data model? → It can create ambiguous filter paths, leading to slower queries and unexpected results
9. Which Power BI feature enables governance by allowing admins to enforce policies on workspace creation and sharing? → Power BI Admin Portal
10. Which data type in Power Query stores whole numbers without decimal places? → Whole Number
11. What is the difference between SUM and SUMX in DAX? → SUM works on columns; SUMX iterates a table row by row
12. Which DAX function creates a virtual table by filtering an existing table based on a condition? → FILTER
13. What is the purpose of a 'decomposition tree' visual in Power BI? → Interactively breaking down a measure across multiple dimensions
14. What is the purpose of a 'Parameter' in Power Query? → A variable value that can be used dynamically within query steps
15. What is query folding in Power Query? → Pushing transformation steps back to the data source to execute natively
16. What is a calculated column in Power BI? → A column computed during query refresh using DAX
17. What does the USERELATIONSHIP function do in DAX? → Activates an inactive relationship for use within a CALCULATE expression
18. For Power BI, you'll need to make a customized visualization. What do you think should be the first thing you install? → Node.js
19. What is Power Query used for in Power BI? → Connecting to data sources and transforming data before loading
20. What does a slicer do in Power BI? → Provides an on-canvas filter that lets report users interactively filter visuals
21. What does 'row-level security (RLS)' enforce in Power BI Service? → Restricts data visibility so users only see rows they are permitted to access
22. In Power BI, what is a 'role-playing dimension'? → A single dimension table used multiple times with different relationships
23. What is a 'dataflow' in Power BI? → A reusable set of Power Query transformations stored in the Power BI Service
24. What does the Power BI Admin Portal allow tenant administrators to manage? → Tenant-wide settings, user permissions, audit logs, and feature controls
25. In Power BI, which relationship filter direction allows filters to propagate in both directions between two tables? → Bidirectional
26. What language do Power Query transformations use behind the scenes? → M (Power Query Formula Language)
27. Which Power BI feature allows you to navigate from a summary visual to a detail report page? → Drill-through
28. What Power BI feature partitions historical data and refreshes only the most recent portion, reducing refresh duration for large datasets? → Incremental refresh
29. What is the default storage mode for tables in Power BI Desktop? → Import
30. What does 'deployment pipelines' in Power BI help you manage? → CI/CD workflows for promoting Power BI content from development to test to production