16.10 - Fallback Data File Space Requirements - Access Module

Teradata Tools and Utilities Access Module Reference

Access Module
July 2017
Programming Reference

The fallback data file requires enough space to save all of the data between two successive checkpoints. If the directory that you specify for the fallback data file does not have enough free space to save all of the data read during the checkpoint interval, then the Teradata Access Module for Named Pipes will not be able to provide all of the data to support a subsequent restart operation.

Always specify a directory for the fallback data file that has enough free space to store all of the data expected during the checkpoint interval.

Example: Fallback Data File

The Teradata FastLoad Reference (B035-2411) recommends checkpoints be taken as follows:
  • Every 100,000 records if each record is less than 4 KB
  • Every 50,000 records if each record is more than 4 KB

These guidelines imply that the fallback data file should range from 200 to 400 MB in size for small- to medium-sized databases. For large databases, the fallback data file might need to be 1 GB or greater.