I've defined my external table definition, but I have one field that could theoretically contain a very long string that I dont care about.
Rather than error out, is it possible to set polybase to truncate long fields that extend over the specified length?
Today it is not possible to truncate during load. It's a great suggestion. You can file a formal request here: https://feedback.azure.com/forums/307516-sql-data-warehouse This is where we capture feedback from the public. Thanks.