A database session is an authenticated, logical connection between the application and the database. Sessions are explicitly connected and disconnected, and while connected provide the vehicle for all communication between an application and the database.
If a session is established for requests that intended to complete quickly, the overhead of establishing and terminating a session may take longer than the actual request. When this is a common occurrence, the overhead may be minimized by using TDP session pools. A session pool establishes sessions once, then allows applications to re-use them. If the logon string for a session matches a session pool, and CLIv2 session options also match session pool attributes, then that session will be used by the application. The CLIv2 DBCAREA options and their correspondence to session attributes on the TDP START POOL command are as follows.
| DBCAREA | START POOL Operand |
|---|---|
| Two-phase commit of 'Y' | TWOPC |
| Transaction-semantics of 'T' | TERADATA |
| Transaction-semantics of 'A' | ANSI |
| Date-form of 'A' | DATEFORM ANSI |
| Date-form of 'T' | DATEFORM TERADATA |
| Language-conformance of '2' | SQL2 |
| Language-conformance of '3' | SQL3 |
| Statement-status of 'E' | STMTSTAT |
For a full description of TDP session pools, see Teradata® Director Program Reference, B035-2416 and Teradata® Manager User Guide, B035-2428.