Performing point-in-time recoveries with change accumulation files

However, note the following considerations:

• After you use a change accumulation file for a point-in-time recovery, neither R+/CHANGE ACCUM nor BMC AMI Recover can use that file again.
• R+/CHANGE ACCUM does not include log records within existing point-in-time recovery ranges when it creates change accumulation files.

In the following figure, the point-in-time recovery uses an existing change accumulation file. Notice that the recovery does not have to include the entire log range of the change accumulation file.

When you perform a point-in-time recovery, SYSIBM.SYSCOPY or BMCXCOPY records the point to which the space is recovered as the point-in-time (PIT) log point. In above figure , the PIT log point is 1312000. When a subsequent recovery is necessary, you cannot use the same change accumulation file because the ending log point of the change accumulation file (14CB000) falls in the existing PIT log point range.

If you want to use change accumulation files instead of Db2 logs to perform a recovery after a point-in-time recovery, you must create change accumulation files at the same time that the point-in-time recovery is performed. (See the following figure.) The log record data used to perform the point-in-time recovery is simultaneously written to the change accumulation file being created. The next time a recovery is performed, BMC AMI Recover can use this change accumulation file instead of the Db2 logs.

The change accumulation file created includes log data from the range 12FF000 to1312000.

When you create a change accumulation file after a point-in-time recovery, the log data needed for subsequent recoveries or change accumulations is maintained on the file. Consequently, log data within the PIT log point range is not included in the file. The following figure shows how two point-in-time recoveries affect which log data is written to a change accumulation file that is created later.