The structure and performance of your CICS® DB2® connection is determined when you define the DB2CONN, DB2ENTRY and DB2TRAN objects. These objects describe the global attributes of the CICS DB2 connection, the relationship between CICS transactions and DB2 resources (including application plans and command processors), the attributes of each type of thread, and the type of thread that each transaction can use. See Overview: How you can define the CICS DB2 connection for an overview of the DB2CONN, DB2ENTRY and DB2TRAN objects. For information about how to define the DB2CONN, DB2ENTRY and DB2TRAN objects using resource definition online (RDO), and a full list of their attributes, see the CICS Resource Definition Guide.
When CICS is connected to DB2 Version 6 or later, and you are exploiting the open transaction environment, you also need to synchronize your setting for the system initialization parameter MAXOPENTCBS with the TCBLIMIT value on your DB2CONN definition. The MAXOPENTCBS system initialization parameter and TCBLIMIT has more information about this.
This section provides further information to help you decide on your DB2CONN, DB2ENTRY and DB2TRAN definitions. The topics What happens during SQL processing and How threads are created, used, and terminated provide more detail about the CICS DB2 environment to help you understand the effects of your choices. To optimize the performance of your CICS DB2 connection, Selecting thread types for optimum performance, Selecting BIND options for optimum performance and Coordinating your DB2CONN, DB2ENTRY, and BIND options provide advice on coordinating your DB2CONN and DB2ENTRY definitions with the options you choose during the bind process.