Hi again @JaneW,
In 1.3.1, Xcalar added the ability to edit column names and data types, specifically for CSV data sources, and not other formats. For other data source formats, such as JSON, data types are implicit in the structure.
I anticipate that we will add additional similar capabilities for other data source formats. Currently, I have no ETA for any such changes.
Let us know what you think of the changes.