16.10 - Restrictions - Teradata Database

Teradata Database SQL Fundamentals

Teradata Database
Release Number
June 2017
Content Type
Programming Reference
Publication ID
English (United States)
Last Update

Most Teradata load utilities cannot access a table that has an active trigger.

An application that uses triggers can use ALTER TRIGGER to disable the trigger and enable the load. The application must be sure that loading a table with disabled triggers does not result in a mismatch in a user defined relationship with a table referenced in the triggered action.

Other restrictions on triggers include:

  • BEFORE statement triggers are not allowed.
  • BEFORE triggers cannot have data-changing statements as triggered action (triggered SQL statements).
  • BEFORE triggers cannot access OLD TABLE, NEW TABLE, or OLD_NEW_TABLE.
  • Triggers and hash indexes are mutually exclusive. You cannot define triggers on a table on which a hash index is already defined.
  • A positioned (updatable cursor) UPDATE or DELETE is not allowed to fire a trigger. An attempt to do so generates an error.
  • You cannot define triggers on an error logging table.