VSO DEDB areas and the PREOPEN and NOPREO keywords

The PREOPEN and NOPREO keywords of DBRC's INIT.DBDS and CHANGE.DBDS commands apply to both VSO DEDB areas and non-VSO DEDB areas.

When a NOPREO area is also defined as shared VSO with a share level of 2 or 3, you can open the area with the /START AREA command. This connects the area to the VSO structures.

You can use the DBRC commands to define your VSO DEDB areas at any time; it is not necessary that IMS be active. The keywords specified on these DBRC commands go into effect at two different points in Fast Path processing:

• Control region startup

  After the initial checkpoint following control region initialization, DBRC provides a list of areas with any of the VSO options (VSO, NOVSO, PRELOAD, and NOPREL) or either of the PREOPEN or NOPREO options. The options are then maintained by IMS Fast Path.

• Command processing

  When you use a /START AREA command, DBRC provides the VSO options or PREOPEN|NOPREO options for the area. If the area needs to be preopened or preloaded, it is done at this time.

  When you use a /STOP AREA command, any necessary VSO processing is performed.

  Related Reading: See IMS Version 15.3 Commands, Volume 2: IMS Commands N-V for details on /START and /STOP command processing.