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

Teradata Vantage™ SQL Data Definition Language Detailed Topics

Product
Teradata Database
Teradata Vantage NewSQL Engine
Release Number
16.20
Release Date
March 2019
Content Type
Programming Reference
Publication ID
B035-1184-162K
Language
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.