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.
- Optional word that can be specified after the FALLBACK keyword.