To restore the database to the most recent synchronization point before the occurrence of an error, take the following actions:

When operation without unloading system log is not used

Execute the pdrstr command using backup file 2, acquired after the time was moved back, and the unload log file in log 2 that was acquired after a backup was acquired.

When operation without unloading system log is used

Execute the pdrstr command using backup file 3, acquired after the time was moved back and HiRDB was started, and the system log file in log 2.

Even if you forgot to acquire a backup after moving back the time, or if the acquired backup files are damaged and unusable, you can still restore the database using the procedure described below.

When operation without unloading system log is not used

1. Using backup file 1 and the unload log file in log 1 acquired before the time was moved back, you can execute the pdrstr command to restore the database to the state it was in when the time was moved back.
2. Using the unload log file in log 2 after the time was moved back, you can execute the pdrstr command to restore the database to the last synchronization point preceding the error.
   

   Note

   Basically, database restoration using only logs must be executed after a restoration using only backups. The above-described restoration procedure when backups cannot be used should be executed only when the time is changed according to the procedure described in this section.

When operation without unloading system log is used

When backup file 3 cannot be used, use backup file 2 to restore the database to the point at which backup file 2 was acquired. If backup file 2 cannot be used either, use backup file 1 to restore the database to the point at which backup file 1 was acquired.