17.10 - transform_specification - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Definition Language Syntax and Examples

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Programming Reference
Publication ID
B035-1144-171K
Language
English (United States)
transform_group
A mandatory name for the transform group.
You can create or replace up to 16 transform groups per UDT. The first transform group you specify is the default transform group. A UDT cannot have two transform groups with the same name.
The name of a transform group cannot begin with the characters TD_, which are reserved as a transform group name prefix for internal use. For information about naming database objects, see Teradata Vantage™ - SQL Fundamentals, B035-1141.
UDT transform names need not be unique across UDTs.
Transform group names are stored in DBC.UDTTransform, not in DBC.TVM.
TO SQL
The tosql routine maps a predefined data type value to a UDT value. The system invokes it automatically whenever a UDT value is transferred to Vantage from a client application.
Note that the external routine invoked by a tosql clause must be an external UDF. It cannot be a method.
FROM SQL
The fromsql routine maps a UDT value to a predefined data type value. The system invokes it automatically whenever a UDT value is transferred from Vantage to a client application.
The external routine invoked by a fromsql clause can be either an external UDF or a method.