There has been a lot of excitement around the newly-added support for reading from Parquet files in Power BI. However I have to admit that I was disappointed not to see any big improvements in performance when reading data from Parquet compared to reading data from CSV (for example, see here) when I first started testing it. So, is Power Query able to take advantage of Parquet’s columnar storage when reading data?
The answer is yes, but you may need to make some changes to your Power Query queries to ensure you get the best possible performance. Using the same data that I have been using in my recent series of posts on importing data from ADLSgen2, I took a single 10.1MB Parquet file and downloaded it to my PC.
It seem like an area of future growth for Power Query, but Chris does show how to eke out some gains right now.