Microsoft Power BI Study Guide 2026

Marking a date table ensures DAX time-intelligence functions work correctly.

Group By aggregates data by grouping rows with the same key column values and applying aggregation operations such as Sum, Count, Min, Max, or Average.

Query Folding means Power Query translates transformation steps into native source queries (like SQL), so the source executes them instead of Power Query processing everything in memory.

A Query Dependency exists when one Power Query query uses another as its source, creating a dependency chain visible in the Query Dependencies view.

Workspaces are collaborative environments in Power BI Service where team members can share and manage reports, dashboards, datasets, and dataflows.

In Power BI, when you need to combine data from multiple tables or queries based on common columns, you use "Join Queries" (specifically, merge queries in Power Query Editor). This operation links rows from two tables, effectively grouping their data together into a single, more comprehensive query result. This is distinct from appending queries, which stacks rows from tables with identical column structures.