Joined: 23 Nov 2006 Posts: 19270 Location: Inside the Matrix
If you do not specify at least a DCB=BLKSIZE, some programs will abend. Some may run but it is safer to go ahead and specify a valid block size.
The difference between a dummy dataset and a temporary dataset is that no file is created when you specify 'dummy'. When you use a temporary dataset, the data will be written to it and can be read back from it. Temporary datasets are managed by the system and are automatically deleted when they are no longer needed.