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Optimize consolidation (append) of tables

Hello all,


Will much appreciate help with the (apparently) simple issue I'm having:


I have a Power BI file that loads information via Power Query of all the Excel files in a folder. I need to calculate the incrementals of figures between some of the atributes (tabs of the Excel files), for example, "optimized scenario" minus "base scenario", to achieve this, I make additional tables to calculate this difference.


All good up to here, runs fairly quickly. the problem is when I want to consolidate all the created tables (always around 12 tables) using the append function, it takes way more time to process than all I have described before. The screen that shows the progress of the load process finishes quickly with all the tables until it reaches the appending part. I made sure that the only thing the final table (the one I append everthing to) does is append, but it always gets stuck there, cycling through each Excel file in the source folder multiple times.


Any idea on how to optimize this would be greatly appreciated, I believe it is a small thing I'm missing that's causing this.


Thanks in advance.



Super User IV
Super User IV

@ImkeF , have any thoughts?


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Hi @Wolfgang7 ,

there could be many reasons. Please check my list here: 


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