DBRC and IRLM support for batch systems in a data-sharing environment

By default, DBRC provides data-sharing support for your batch and utility regions.

To change the default, you can either:

• Assemble and bind DFSIDEF0 into the IMS execution library (If you specify RMODE, you must specify RMODE=24 and AMODE=24)
• Override the value in a DFSPBxxx IMS PROCLIB member data set
• Override the value in JCL

To define the default IRLM support specifications for batch systems in a data-sharing environment, use the IRLM= keyword on the IMSCTRL macro. You can override specifications made in the IMSCTRL macro by using the IRLM= keyword in the batch JCL.

In batch systems, you can specify IRLM=Y or IRLM=N. If you specify IRLM=N:

• IRLM does not perform locking for the batch system.
• The batch system cannot participate in block-level sharing.

When batch systems do not use IRLM, DBRC still ensures the integrity of databases. DBRC authorizes batch jobs that have update access to a database only if all other IMS systems and batch jobs that are currently authorized by DBRC to the database have read-only access.