Rules for Order Mapping UDFs | CREATE ORDERING | Teradata Vantage - Rules for Order Mapping UDFs - Advanced SQL Engine - Teradata Database

If you specify a UDF as the MAP routine for an ordering, it must obey the following rules:

• It must have one and only one parameter.
• The data type of the single parameter you specify must be the same as that of the UDT specified as UDT_name.
• The result data type must be a predefined data type.
  Its predefined data type is valid except the following:

  • BLOB
  • CLOB
• It must be declared to be DETERMINISTIC.
• The name you specify for it in the ordering definition must be the name of a UDF contained within the SYSUDTLIB database.