@AJ2020 this is an interesting question.

are you asking for max columns you can read in via a connector? or maximum columns you can create in ETL?

I believe the max columns is 1024 but i'm probably wrong.

More importantly... why are you hitting the max number of columns? Could you shape the data in a way that's more useable? (particularly if you're working with a connector that adds columns based off of distinct values in a JSON array, you'll want to reconsider b/c from day to day the shape of the dataset could change).

i believe Domo support can lift an arbitrary limit ... but again, why would you have a multi-hundred-column dataset and more importantly could you use it in a way that makes sense?