TurboIMAGE/XL Database Management System Reference Manual MPE/iX V6.5 (30391-90011)

400 Chapter8
Using the Database Utilities
>ROLLBACK
>ROLLBACK
Rolls out any incomplete transactions following a system crash. Multiple databases can be
roll-back recovered concurrently by entering the command as follows:
>ROLLBACK dbname, dbname
Syntax
>ROLLBACK dbname [/ maint word ][ .group [ .account ]]
Parameters
database name is the name of individual database(s) to be rolled-back.
maint word is the maintenance word defined by the database creator. This word must
be supplied by anyone other than the database creator.
group is the group where the database(s) resides.
account is the account where the database(s) resides.
Discussion
If the >ROLLBACK command is accepted, the following message is returned:
DATABASE database name LAST USED day, date, time
The following conditions must be satisfied before the >ROLLBACK command is accepted:
1. The database must be accessible to the user (database administrator) running
DBRECOV. This user must either be the creator of the database or know the
maintenance word. If the database resides in a group or account different from the
user's on, the MPE/iX file security must permit the user read and write access to the
database files.
2. The database must have been enabled for roll-back recovery.
3. The log identifier characteristics (name, password, log file name and device type) must
not have been altered since the log file was generated. This restriction applies to
MPE/iX log commands as well as those provided by TurboIMAGE/XL by DBUTIL. This
is necessary because the MPE/iX log identifier is used by TurboIMAGE/XL to obtain the
name and device of the log file.
4. When roll-back is enabled, DBUTIL sets a roll-back flag to indicate that roll-back is
enabled for the database. The roll-back time stamp is updated when the database is
first opened and is logged to the log file. Roll-back recovery then uses the time stamp
during recovery to verify the correct log file for each database.
5. No other users can be accessing the database when >ROLLBACK is called. The database