Idea: to migrate the data, a JS function could be provided together with a test function or even a few pairs of examples (before -> after) to help ensure it works well. Additionally, Xata could run the function in 50 random records and show the results so the user can approve or reject the data migration with confidence. This could be useful not only for when one needs to change a column type, but when they need to change the format of the values in a column even if it's "officially" the same type.