The Teradata PT parallelism-enabling protocol can be used in multi-node, multi-process, and multi-threaded applications. Teradata PT allocates the sessions as evenly as possible among the main and the worker instances. Each instance is connected with the number of sessions equaling the max-session value divided by the number of instances. Multiple parallel instances are used to load and export rows to and from the database target tables. For example, Teradata PT load parallel applications can load data into the same table on different nodes, as shown in the following illustration:
The same parallelism-enabling protocol is supported in all four Teradata PT drivers to provide a consistent application interface. However, since the Stream driver does not require the database to lock the target tables that are being updated, the choice can be made to run multiple parallel Stream application jobs instead of multiple instances in multi-node, multi-process, and multi-threaded applications.
The main and the workers must run on the client machines that have the same endian mode (big-endian mode or little-endian mode). For mainframe-attached z/OS platforms, the main and workers must all run on mainframe-attached z/OS platforms.