EXPAND ON is a Teradata extension to the ANSI SQL:2011 standard.
Because of this, the database reports a warning message if you use an EXPAND ON clause in a session in which the SQL Flagger is set. For information about the SQL Flagger, see Teradata Vantage™ - SQL Fundamentals, B035-1141.
The Teradata SQL EXPAND ON clause does not share any functionality with the EXPANDING clause of the ANSI SQL:2011 standard.