16.10 - LogTable - Parallel Transporter

Teradata Parallel Transporter Reference

Product
Parallel Transporter
Release Number
16.10
Published
July 2017
Content Type
Programming Reference
Publication ID
B035-2436-077K
Language
English (United States)

A restart log table, which contains restart information written during job runs, is required for any execution of the Update operator. Specify a restart log table in scripts with the LogTable attribute.

Restarts (as discussed in Staged Loading) are common during staged loading operations. When additional data is available after a job is paused, the job is restarted by submitting a second script that specifies the additional data. The Update operator recognizes the job as a restart, reads the restart log to determine the status of the job, then loads the additional file.

Restarts can also occur following any unexpected error on a database. For example, if a table runs out of available space during a load operation, the job terminates, the table is paused, and a checkpoint is recorded in the restart log. Pausing the job in this way allows you to manually increase the available space, if needed, then restart the job because the load operation can restart a job from the last checkpoint in the restart log.

If you do not specify a name for LogTable, the Update operator automatically creates a name of the log table as follow:

ttname_RL

wherettname is the name of the first target table.

The value of the TargetTable attribute is truncated to 27 characters before the suffix "_RL" is appended. This means that if the value of the TargetTable attribute is a fully qualified table name and the fully qualified name exceeds the maximum supported length of a database object (30 characters), the generated names for the log table may not be what you intend. In such a case, Teradata recommends that you provide the names of the log table and not rely on the Update operator to generate the names for log table automatically.