SUBSTRING and SUBSTR operate on the following types of arguments:
If the string_expression argument is numeric, it is implicitly converted to CHARACTER type.
- UDTs that have implicit casts to any of the following predefined types:
To define an implicit cast for a UDT, use the CREATE CAST statement and specify the AS ASSIGNMENT clause.
Implicit type conversion of UDTs for system operators and functions, including SUBSTRING and SUBSTR, is a Teradata extension to the ANSI SQL standard. To disable this extension, set the DisableUDTImplCastForSysFuncOp field of the DBS Control Record to TRUE.