Data Mover provides the ability to independently specify the number of source and target sessions that a job uses when transferring data. When creating jobs through the command-line interface, the number of sessions used can be specified with the source_sessions and target_sessions parameters when using the create or move command.
Specifying a higher number of sessions can improve individual job performance, although specifying too many sessions can lead to performance degradation. The optimal number of sessions varies depending on the environment and the utility being used. Consult Teradata® Parallel Transporter Reference and Teradata JDBC Driver Reference for details.
If a value for the source and/or target sessions is not provided, Data Mover dynamically determines the number of sessions; this determination is based on multiple factors, including number of AMPs, size of objects being moved, and so forth. This dynamic value is a good starting point, but advanced users may find more ideal settings to use for each situation.