Fallback vs. Nonfallback Tables
Target tables can be either fallback or nonfallback.
Table 10 lists the differences between, and characteristics of, these tables.
Fallback Tables |
Nonfallback Tables |
Teradata TPump task continues to execute even if AMPs are down, as long as there is not more than one AMP down, either logically or physically in a cluster. |
If one or more AMPs are down prior to entering the task and if one or more target tables are nonfallback, Teradata TPump terminates. |
If two or more AMPs in a cluster are logically or physically down, or both, the task does not run, or terminates if running. |
The Teradata TPump task may be restarted as soon as all AMPs are back up. |
During the task, if AMPs are down to the extent that data on the disk is corrupted, the affected tables must be restored. |
If an AMP goes down once the task has started, the task cannot be restarted until all AMPs are back up. |
Not applicable. |
If more than one AMP in the same cluster is down, Teradata Database cannot come up. |
Not applicable. |
Certain I/O errors during the task corrupt the target table so that it must be restored. In this case, Teradata TPump terminates. |