Forum Discussion
Prefer CSV or JSON for my dataflows
Hi, I am new to PowerBI and will appreciate any help with my question. I have created multiple dataflows which extracts data from folder locations in my file system with the help of an on-pr...
I can't find it at the moment but I did see a blog comparing load times and think csv came out top. Under the hood when you run a data flow it stores the data as csv in azure data lake storage so it's very optimised for that sort of thing.
My hunch would be that you're unlikely to notice a huge difference. (Worth testing!)
One thing to consider that will make a difference if you're reading lots of csv (or json) in is two separate the ingest from transformations in dataflows (assuming you have premium or premium per user).
Create a first data flow that simply pulls in the raw data.
Then create a second which uses the ingested data in the first to do transformations on.