If arg is not FLOAT, it is converted to FLOAT based on implicit type conversion rules. If the argument cannot be converted, an error is reported.
If arg is a UDT, the following rules apply:
- The UDT must have an implicit cast 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 LN, is a Teradata extension to the ANSI SQL standard. To disable this extension, set the DisableUDTImplCastForSysFuncOp field of the DBS Control Record to TRUE.
LN cannot be applied to the following types of arguments:
- BYTE or VARBYTE
- BLOB or CLOB
- CHARACTER or VARCHAR if the server character set is GRAPHIC