In case you would like to troubleshoot complex DAX formulas within the Power BI environment, some helpful and simple approaches can help identify the problem and understand the cause of the problem more easily:
- Divide and Conquer: this allows you to break down a complicated formula into smaller and usable parts. Solving a math problem may take a step-by-step approach without solving it in a single move. The same goes with DAX. Do not attempt to correct the entire formula all at once; divide it into parts. For each section of the formula, try coming up with a smaller calculation or measure and see if these work as expected. After each part performs as intended, then you can reassemble them into one piece.
- The next approach is the Use of Variables, which aids in avoiding excess complexity in DAX expressions: Consider variables as temporary containers for some results. Why do some of you have to repeat the same lengthy formula, and some of you do not? Instead of repeating the same expression every time, it can be substituted and put in a reusable variable. This not only enhances the clarity of the code but also allows the programmer to examine the status of the contents at every stage, which assists in tracing errors.
- Break Down the DAX Formula into Smaller Parts: Removing unnecessary complexity enables the users to simplify complex DAX formulas to the extent that they will be ready to use each of the supplied simpler formulas to create the desired combined formula once more. There is no guarantee that the app's waiting time will be shorter than for the initial state where the DAX expression is presented in airplane mode.
- Restructure your DAX Code: If your DAX expression appears as a jumble, it will be more difficult to identify errors. While writing DAX code, it would be better to use the DAX Formatter and get your code cleaned and organized. In fact, properly indented and structured code will enhance readability, and it will be apparent which sections of code may have issues. It is more than likely that one of your DAX formulas is performing a lengthy calculation, which is why your report is running slowly.
- All DAX functions, measures, or queries will be displayed within this window, and their execution times can be measured with some focus on the timing itself. If you have a certain page in your report that is slow, you can check which measure takes the longest to execute using this tool and, therefore, which measure you should troubleshoot.
Hence, there are ways to troubleshoot advanced DAX calculations systematically. Moreover, the query can be broken down into even smaller pieces:
