Joined: 23 Nov 2006 Posts: 19270 Location: Inside the Matrix
Delete is usually specified before a define to ensure that any previoiusly created contents are removed. If it is always in the control statements, there is no need to have separate runs depending on if this is a new file or an already existing file.
The define pre-formats/initializes the dasd allocated for the VSAM "file".
For complete understanding of the define parameters, please refer to the vsam manual.
An easy way is to look at one of your application's vsam definitions and then find the corresponding parameters in the manual - you will see what your definition means as well as other options that might have been chosen.