An optional expression that evaluates to a valid BYTE(4) row hash value.
If expression results in a UDT, Teradata Database performs implicit type conversion on the UDT, provided that the UDT has an implicit cast to a predefined byte type.
To define an implicit cast for a UDT, use the CREATE CAST statement and specify the AS ASSIGNMENT clause. For more information on CREATE CAST, see Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144.
Implicit type conversion of UDTs for system operators and functions, including HASHBUCKET, is a Teradata extension to the ANSI SQL standard. To disable this extension, set the DisableUDTImplCastForSysFuncOp field of the DBS Control Record to TRUE.