Microsoft Power BI Data Analyst Practice Question

The correct answer is to use the Performance Analyzer. The Performance Analyzer is a built-in tool in Power BI Desktop designed specifically to diagnose performance issues with report elements. By starting a recording and then interacting with the report page (e.g., refreshing visuals or changing a slicer), the analyst can see a detailed breakdown of the duration for each visual. This breakdown includes the time spent on the DAX query, the time for the visual to render, and other processing time. This allows the analyst to pinpoint exactly which visual or underlying DAX query is taking the longest, which is the essential first step in optimization.

Using DAX Studio is a powerful next step for deep query analysis, but the initial identification of the slow element is best done with the integrated Performance Analyzer. Reducing data granularity is an optimization technique, not a diagnostic step; you would apply it after identifying the problem area. Modifying relationships in the model view might be necessary, but it is not the first step for diagnosing which specific visual on a page is slow.