Access to linear data sets

You can access a linear data set with VSAM, the DIV macro, or window services.

To update a linear data set using VSAM, you must use control interval access, and must have control authority. To read a linear data set with VSAM, you must use control interval access, and must have read authority. For more information, see Processing control intervals, especially Access to a control interval. See also the DEFINE CLUSTER topic in z/OS DFSMS Access Method Services Commands for available options and associated restrictions for the LINEAR parameter.

The following family of window services for accessing linear data sets is described in z/OS MVS Programming: Assembler Services Guide and z/OS MVS Programming: Assembler Services Reference ABE-HSP:
  • CSRIDAC -- Request or terminate access to a data object
  • CSRVIEW -- View an object
  • CSREVW -- View an object and sequentially access it
  • CSRREFR -- Refresh an object
  • CSRSCOT -- Save object changes in a scroll area
  • CSRSAVE -- Save changes made to a permanent object

For information about using data-in-virtual (DIV), see z/OS MVS Programming: Assembler Services Guide.