Teradata PT allocates the sessions as evenly as possible among the master and the slave 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 Teradata 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:Figure 7: Master and Slave Parallel Relationships during Load and Export
Note: Multiple threads should not share the same Teradata PT Connection object.
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 Teradata 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 master and the slaves 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 master and slaves must all run on mainframe‑attached z/OS platforms.