DDN keyword

DDN keyword on function control statements

You can use the DDN keyword on function control statements (IC and AIC, OIC and AOIC, CIC and ACIC, IIC and AIIC, REC and AREC, and TRACE) to specify the ddname associated with the data set group to be processed.

The DDN keyword is valid only for full-function databases (including HALDBs); for DEDBs, specify the AREA keyword.

For full-function, non-HALDB databases, the value of the DDN keyword is the ddname associated with a data set group in the database definition. If the DDN keyword is omitted on control statements where it is optional and the database contains more than one data set group, you are implicitly requesting processing of each data set group that is defined in the database. The output image copies must be dynamically allocated. For the CIC, ACIC, IIC and AIIC functions, the input image copy data sets must be dynamically allocated. If the database contains only one data set group, you can omit the DDN keyword.

For HALDBs, the following considerations apply to the use of the DDN keyword:

• To process all data set groups in all partitions in a HALDB implicitly, omit the DDN keyword and specify the DBALLOC(Y) keyword on the GLBL control statement.
• To process all data set groups within a partition implicitly, specify the partition name with the DDN keyword.
• To process individual data set groups within a partition, specify the data set group name with the DDN keyword.

DDN keyword on STACK and CHKPT control statements

The DDN keyword is required on STACK control statements and optional on CHKPT control statements.

You use it to specify the ddname to use for the stack or checkpoint data set or to specify a dynamic allocation model to use for dynamic allocation of the stack or checkpoint data set. If you do not specify it on a CHKPT control statement, the default name ICPCHKPT is used.