16.20 - Triggers and Identity Columns - Teradata Database - Teradata Vantage NewSQL Engine

Teradata Vantage™ SQL Data Definition Language Detailed Topics

Teradata Database
Teradata Vantage NewSQL Engine
Release Number
March 2019
Content Type
Programming Reference
Publication ID
English (United States)

The following rules and restrictions apply to triggers and INSERT operations into tables with identity columns.

  • You cannot create a trigger definition if its triggering statement is an INSERT on a subject table that has an identity column and its triggered action statement or WHEN condition references that column.
  • If a triggered statement makes row references to the table that is involved in the triggering statement, and the triggered statement is an INSERT operation into a table with a GENERATED ALWAYS identity column, Teradata Database substitutes a dummy value for the USING value for the referenced row and then generates the actual identity column number in the Dispatcher before sending it to its destination AMP.