Exploring PDSEv2 member generations

Use the PDSEv2 Generations view to browse, compare, copy, and delete partitioned data set extended version 2 data set member generations.

About this task

Partitioned data set extended version 2 (PDSEv2) can retain a number of generations of data set members. Generations of a PDSEv2 member are identified by numbers. The current generation is always 0, and previous generations are numbered with positive integers. If a PDSEv2 member has 10 generations, for example, the current generation is 0, the oldest generation is 1, and each subsequent generation number is incremented by 1. The following screen capture shows a PDSEv2 member with four generations. The most recent member generation is 0, the next most recent generation is 4, and the oldest generation is 2.

When you allocate a PDSEv2, you specify the maximum number of generations. The default value is 0. When a PDSEv2 member exceeds the maximum number of generations, the oldest generation is discarded. Data set I/O functions, such as read, write, rename, or delete, operate on the current generation.

You can use the PDSEv2 Generations view to browse, compare, copy, and delete partitioned data set extended version 2 data set member generations. For more information about PDSEv2 member generations, see the related topics.

Note: Operations that you perform in the PDSEv2 Generations view are different from similarly named operations in the Remote Systems and z/OS Projects view.

• The Open, Browse, Delete, Copy to the New Generation, Copy, and Compare With menu items in the PDSEv2 Generations view operate on the selected generation.
  
• The Open, Browse, Delete, Copy, and Compare With menu items in the Remote Systems and z/OS Projects views operate on the current generation.
  

The Delete menu item, for example, in the PDSEv2 Generations view deletes only the selected generation. All other generations remain. The Delete menu item in the Remote Systems and z/OS Projects views deletes the current generation and all previous generations of the member. The Rename menu item in the Remote Systems and z/OS Projects views renames the current generation and deletes all previous generations of the member. The Search menu item in the Remote Systems and z/OS Projects views searches only the current generation.

1. To open the PDSEv2 Generations view:
   1. In the Remote Systems view or the z/OS Projects view, select a PDSEv2 member.
   2. Right-click and select PDSEv2 Generations.
2. Select one or more member generations, and then right-click and click one of these menu items. To select multiple member generations, press and hold the Ctrl key while you make your selections.

   Option	Description
   Open	Opens the selected generation in an editor. This menu item is enabled only when the current generation (0) is selected.
   Browse	Opens the selected generation in read-only mode in an editor. You cannot modify the content in the editor.
   Delete	Deletes the selected generation and refreshes the view. Deleting a generation might create a gap in generation numbers. This menu item is available only when previous generations are selected.
   Copy to the New Generation	Creates a new generation, copies the content of the selected generation to it, and refreshes the view. This menu item is enabled only when one generation is selected.
   Copy	Copies the content of the selected generation to the clipboard. The copy can be pasted as a new member of a partitioned data set in the Remote Systems view or z/OS Projects view.
   Compare With > Each Other	Opens two generations in the comparison editor in read-only mode. This menu item is enabled only when two generations are selected. Older generations are opened in read-only mode.