16.20 - FALLBACK - Teradata Database - Teradata Vantage NewSQL Engine

Teradata Vantage™ SQL Data Definition Language Syntax and Examples

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

Duplicate copy protection for the table.

When you specify FALLBACK, Teradata Database creates and stores duplicate copies of rows in the table.

The default for this option is established by a CREATE DATABASE, CREATE USER, or MODIFY USER statement for the database or user in which the table is to be created.

When an unrecoverable bit error occurs, the system reads the fallback copy of the data. Support for unrecoverable bit error recovery using fallback is limited to the following cases:

  • Requests that do not attempt to modify data in the bad data block
  • Primary subtable data blocks
  • Reading the fallback data in place of the primary data. The system does not attempt to fix the bad data block.
No duplicate copy protection for the table.
You cannot use the NO FALLBACK option and the NO FALLBACK default on platforms optimized for fallback.
Optional word that can be specified after the FALLBACK keyword.