My workbook is using TDE which needs to be refreshed incrementally on a daily basis. The data source is a custom_sql with 15 columns. I have a last_update_date column in my SQL. I want to incrementally refresh based on last_updated_date. But when I follow the steps to incrementally Refresh Extracts I see only 3 columns out of the 15 columns in my custom SQL listed in the drop down list. Why I am not seeing all 15 columns listed in the drop downlist ? How to configure tableau to show all 15 columns in the "Identify new rows using column" drop down list ?