How many dd statements in a job

Folks, again, it would be nice if you would cite your sources for your answers. Posted: Sat Feb 26, pm. Hi meetsrk, max dd sttements are and it depends on TIOT control block size specified at the time of installation.

Posted: Sun Feb 27, am. The ques was: Quote:. Posted: Mon Feb 28, pm. The limit of is applicable to the concatenation also. But it depends on the pgm that is going to read the concatenated datasets.

For 16K, upto DDs supported, I hope Posted: Tue Mar 22, pm. PLZ illustrate with an example. Posted: Fri Aug 26, pm. I found a reference that hopefully answers this question.

The system can retrieve two or more data sets and process them successively as a single sequential data set. This is called sequential concatenation. By specifying an integer from 16 to 64 as the value of this parameter, the installation controls the default DD allowance. The count of entries in the TIOT is the count of candidate volumes for the data and index components plus: For a reusable data set - the number of volumes used by the data component plus the number of volumes used by the index component.

For a nonreusable data set - the number of volumes in the set of volumes used by the data and index component. Twenty bytes for the basic information for the first unit and an additional four bytes for the second unit. Value Range: 16 - 64 kilobytes Default: 32 kilobytes. Posted: Wed Dec 18, pm. Sory, it was 64k instead of 32k. Thanks enrico for correction. View previous topic :: :: View next topic. You can use one or more parameters based on requirements and they are separated by comma:.

The DSN parameter refers to the physical dataset name of a newly created or existing dataset. The DSN value can be made up of sub-names each of 1 to 8 characters length, separated by periods and of total length of 44 characters alphanumeric. Following is the syntax:. Temporary datasets need storage only for the job duration and are deleted at job completion.

This is called Backward Referencing. The DISP parameter is used to describe the status of the dataset, disposition at the end of the job step on normal and abnormal completion. DISP is not required in a DD statement only when the dataset gets created and deleted in the same job step like the temporary datasets. OLD : The dataset is already created and will be overwritten in the job step.

The job step gains exclusive access on the dataset and no other job can access this dataset until the completion of the job step. SHR : The dataset is already created and will be read in the job step. The dataset can be read by multiple jobs at the same time.

MOD : The dataset is already created. This disposition will be used when there is a need to append new records to the existing dataset existing records will not be overwritten.