Command processing in a dynamic resource definition environment

If you are running without DRD enabled, the control blocks that manage the resources (DDIRs, PDIRs, SMBs, and RCTEs) are loaded from the MODBLKS data set at cold start. If a type-1 command is issued to change the attribute of a resource (such as the database access type or the transaction class), the internal control blocks are updated and the changes are recovered across a warm or emergency restart. If you perform a cold start, however, the control blocks are reloaded from the MODBLKS data set, so the updated attributes revert to the original values unless you have updated your MODBLKS data set.

If you are running with DRD enabled, any changes that you make to resource definitions by using type-1 or type-2 commands persist across a warm or emergency restart. These changes also persist across a cold start if the updated resource definitions are exported to either a resource definition data set (RDDS) or the IMSRSC repository, and then imported from the RDDS or the repository during cold start. When you export the resource definitions to an RDDS or the repository, all the current attribute values are exported. If you change the value of one of the attributes by using a type-1 or type-2 command (such as the database access type or the transaction class), the updated attribute is exported. The updated attribute values are then imported during cold start if automatic import is enabled.