CA IDMS allows users to specify numerous run-time options for a Central Version (CV) via the PARM= parameter on the jobstep’s EXEC card. These options are defined in Appendix G: Specifying Run-time Options in the CA IDMS System Operations Guide. However in the z/OS environment the operating system limits the total length of the values passed through the PARM= parameter to 100 bytes. The CV options can be abbreviated but some users may still run into the 100 character limitation.
Starting with Release 2.1 of z/OS IBM has provided a new parameter, PARMDD=, which can be used in place of the PARM= parameter. PARMDD= specifies the DDNAME of a file within the CV’s start-up JCL that will contain those options previously supplied using PARM=. A string length of up to 32760 characters is allowed by z/OS but currently CA IDMS limits the total length of the string passed to 256 characters. Details of the use of the PARMDD= parameter can be found in z/OS MVS JCL Reference.
Coding the CA IDMS options
The coding of the options within the file specified on the PARMDD= parameter is rather forgiving in terms of format. The following two examples provide alternate formats for the coding of the CA IDMS CV options. The first example codes each option on a separate record within the file starting in column 1. In both examples a record length of 80 was used to define the PARMDD file.
Within the startup JCL it is necessary to include the PARMDD= parameter on the EXEC card and later within the JCL the specified DDNAME must be included as in the following example.
//R180DC70 EXEC PGM=RHDCOMVS,REGION=0M,TIME=1440,PARMDD=PARMS
//PARMS DD DSN=MEN.C1300.TECHDC70.R185.PARMS,DISP=SHR
To be able to utilize the PARMDD= parameter it is necessary for module RHDCOMVS to be relinked using the LONGPARM=YES command. This parameter is only valid for z/OS 2.1 and later releases. The following example provides the BINDER statements that should be used to relink RHDCOMVS. Each statement starts in column 2.
Where LOADMOD points to the load library containing your current RHDCOMVS module.
An attempt to execute a CV that contains the PARMDD= parameter on the EXEC statement without RHDCOMVS properly linked with the LONGPARM=YES parameter will result in an ABEND306-44 error.