DB2 Version 4.1: Stored Procedure Access to VSAM, CICS, and IMS

Stored Procedure Access to VSAM, CICS, and IMS

Stored procedures can access CICS systems by using:

Message Queue Interface. MQI calls are used for asynchronous execution of CICS transactions.
External CICS Interface (EXCI). EXCI is used for synchronous execution of CICS transactions. The EXCI permits a non-CICS program (such as a stored procedure) to call a program running in a CICS/ESA V4.1 region, and pass and receive data via a COMMAREA. For further information, see pages 50-56 of IBM "red book" publication SG24-4693-00, Getting Started with DB2 Stored Procedures. The red book includes a sample program and implementation tips.

Stored procedures cannot access IMS data directly, for architectural reasons (IMS does not support multiple TCBs for batch processing). MQI can be used to invoke IMS transactions asynchronously. Both MQI and EXCI can be used to invoke CICS transactions that access IMS data.

VSAM files and flat files can be accessed directly by stored procedures, as long as the files are made available to the SPAS with appropriate JCL DD statements. In such cases, the userid associated with the SPAS address space is used to check authorizations.