To recover a VSAM sphere, CICS® VR must have the following information.
For backups made using the backup-while-open facility, CICS VR need not process a log from file-open time. Here, TURs for all open files are regularly written on the log during activity-keypoint processing. To reduce the number of TURs if the activity keypoint frequency is high, CICS ensures that there is at least a 30-minute separation between sets of TURs on the log. The recovery point is a time that can be converted to a position on a forward-recovery log. It is also the point when CICS VR forward recovery starts for VSAM data sets eligible for backup-while-open processing. Recovery of the data set requires only the records that are written after that position. Thus, CICS VR can ignore all previous records.
The recovery point is stored in the ICF catalog. It is set when the first file is opened for update against the data set, and it is updated during activity-keypoint processing and when the file is closed.
The recovery point is not the time of the current keypoint, because there might still be some uncommitted log records that have not been forced. Instead, it is the time of the start of the last keypoint that wrote a complete set of TURs and that completed earlier than the oldest uncommitted write to a forward-recovery log.
CICS VR extracts the recovery point time of the restored backup from the RCDS or ICF catalog. It is not necessary or recommended to specify a STARTTIME keyword in your recovery run.