An application can achieve true parallel request processing by using more than one Teradata Database session. The application can then dispatch several requests simultaneously, one on each session.
How It Works
Each concurrent request can be identified to CLI by using the id of the session with which it is associated (that is, the value in Output Session Id from a call to DBCHCL for the Connect function) and its own id (that is, the value in Output Request Id from a call to DBCHCL for the Connect, Initiate Request, or Run Startup function).
Using Tokens
The application may also supply a token for each request when it is initiated. That token is returned by the DBCHWAT routine when a request’s response arrives.
An application may have requests pending on several sessions simultaneously. One way for the application program to wait is to call an asynchronous wait using DBCHWAT. The wait ends when any outstanding request completes.