- Control SQL Session
- A session that executes SQL requests related to utility work. Almost all Teradata utilities have a control SQL session.
- Auxiliary SQL Session
- An optional, second SQL session maintains a restart log for recovery.
- Utility Sessions
- One or more sessions are used for sending and receiving data to and from Teradata Database.
|Utility Names||Control SQL Session||Auxiliary SQL Session||Utility Sessions|
|FastLoad, MultiLoad, FastExport||Yes||Yes||Yes|
|Teradata Parallel Transporter Load, Update, and Export operators||Yes||Yes||Yes|
|MLOADX||Yes||Yes||Yes (using SQL sessions)|
|JDBC FastLoad, JDBC FastExport||Yes||No||Yes|
|CSP Save Dump||Yes||No||Yes|
- Query session
Utility sessions are subject only to utility session rules.
TASM and Teradata utilities treat the whole load/unload process as one Unit of Work. A Unit of Work starts with the BEGIN LOADING/MLOAD/EXPORT request on the control SQL session. It ends with the END LOADING/MLOAD/EXPORT request. This means that a utility Unit of Work spans multiple SQL requests. Only the first SQL request of a unit on the control SQL session satisfies the utility classification criterion and is assigned to a utility workload. Subsequent requests are assigned to the same utility workload. SQL requests outside the load/unload unit and SQL requests from the auxiliary SQL session can be assigned to different workloads. All applicable throttle counters are checked and incremented only at the beginning of a unit and decremented only at the end of the unit. For backup and restore, the entire script is treated as one unit.