Operation of the persistent data store

Maintenance is invoked automatically by the KPDMANE program.

Important: The content in this section was created for and applies to the original persistent data store, referred to as PDS V1. A new PDS version (referred to as PDS V2) now exists. PDS V1 will eventually be deprecated.

The KPDMANE program invokes maintenance in two places:

On startup, while reading and processing data sets, KPDMANE examines internal data to determine whether each data set is in a known and stable state. If not, KPDMANE issues a RECOVER command.
When KPDMANE is recording information from applications onto an active data set for a group, if it detects that it is running out of room, it executes the SWITCH command internally.