Google Cloud Dataprep Documentation Documentation to_col Parameter Identifies name of the column to which to rename. Multiple column names are not supported. Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 3.0 License, and code samples are licensed under the Apache 2.0 License. For details, see our Site Policies. Java is a registered trademark of Oracle and/or its affiliates. Last updated January 23, 2018.