CICS Resource Definitions

CICS cannot use anything it does not know about. Resource definitions tell CICS about your programs, transactions, files, maps and queues.

What is a resource definition

• A resource definition describes one CICS resource: its name, its attributes, and where it lives.
• Definitions are stored in the CICS System Definition (CSD) file and installed into the running region.
• The modern way to create them is RDO (Resource Definition Online) with the CEDA transaction.
• Until a definition is installed, programs get errors like “program not found” even though the load module exists.

The four classic tables

• PCT — Program Control Table: maps each transaction id to the first program to run.
• PPT — Processing Program Table: lists programs and their attributes (language, residency).
• FCT — File Control Table: maps file names used in programs to real VSAM datasets.
• TCT — Terminal Control Table: describes the terminals connected to CICS.
• These assembler tables are the old method; today each one is a CEDA resource type: TRANSACTION, PROGRAM, FILE, TERMINAL.
• Other common resource types are MAPSET, TDQUEUE, TSQUEUE (model), and DB2CONN for DB2.

Defining resources with CEDA

• Group related definitions in a GROUP so you can install them together.
• DEFINE creates the definition; INSTALL makes it active in the running CICS.
• Define the TRANSACTION with its first PROGRAM, then define the PROGRAM itself.
• Example — type these on a CICS screen under the CEDA transaction:-
  
  *--- Type these on a CICS screen (CICS transaction CEDA) ---* CEDA DEFINE TRANSACTION(MNT1) GROUP(MYGROUP) PROGRAM(CUSTMNT1) CEDA DEFINE PROGRAM(CUSTMNT1) GROUP(MYGROUP) LANGUAGE(COBOL) CEDA DEFINE MAPSET(MNTSET1) GROUP(MYGROUP) CEDA INSTALL GROUP(MYGROUP)