17.10 - Default Capabilities of Structured UDTs - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Definition Language Detailed Topics

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Programming Reference
Publication ID
B035-1184-171K
Language
English (United States)
Unlike the case for distinct UDTs, the system does not automatically generate any transform, ordering, or cast functionality for a structured UDT. You must explicitly provide these capabilities yourself by writing an external C or C++ routine and then creating the appropriate cast, ordering, and transform definitions using the following DDL statements:

You must create explicit ordering and transform functionality for all structured UDTs that you create. If you attempt to specify a structured UDT as the data type for any column of any table, but you have not created ordering and transform functionality for that UDT, the system returns an error to the requestor.

You are not required to create explicit casting functionality for a structured UDT; however, you must create a cast if the structured UDT is to perform in certain SQL expressions such as the USING modifier, or to participate in various loading operations such as Fastload and MultiLoad.

Enabling Full Functionality For a Structured UDT summarizes the implications for structured UDTs of this and the topics that follow by explaining which functionalities must be explicitly user-defined before a newly created structured UDT can be used as the type of a column table.