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

308 Chapter7
Logging and Recovery
Database Utilities Used in Logging and Recovery
Database Utilities Used in Logging and Recovery
The TurboIMAGE/XL database is maintained using various TurboIMAGE/XL database
utilities which are fully described in chapter 8. Because the following database utilities are
used in logging and recovery, they are also referred to in this chapter:
DBUTIL Creates and maintains the database.
DBUNLOAD Copies data to specially formatted tape volumes.
DBLOAD Loads data from backup volumes (DBUNLOAD tape) into the database.
DBSTORE Stores a database to tape. You may also use TurboSTORE/iX 7x24
True-Online Backup with ONLINE=START or ONLINE=END option.
DBRESTOR Restores a database from backup volumes (DBSTORE tape) to disk.
If you use TurboSTORE/iX 7x24 True-Online Backup with
ONLINE=STARTor ONLINE=END option to store your database, you can
use the MPE RESTORE command which invokes TurboSTORE/iX 7x24
True-Online Backup to restore the database.
DBRECOV Recovers a database from a log file, even when you used TurboSTORE/iX
7x24 True-Online Backup with ONLINE=START or ONLINE=END
option to store the database. The DBRECOV utility allows you to set control
commands and create individual user recovery files. The information from
these files enables you to inform each user where to resume transactions
within the database.
Database utilities can be run in either job or session mode. With the exception of the
DBUTIL >>SHOW command, the utilities DBUTIL, DBSTORE, DBRESTOR, DBUNLOAD, and
DBLOAD all require a logon in the group and account that contains the database root file.
Consequently, these utilities cannot be used with a remote database unless you initiate a
remote session and run the utility as part of that session. The DBUTIL, DBSTORE, and
DBRESTOR utilities do not allow you to use the MPE/iX FILE command to equate a
database or database-access file.
CAUTION DBUNLOAD and DBLOAD do allow MPE/iX FILE commands to equate a database
and can redirect the database to a different file. Except in a controlled
environment, you should not use the MPE/iX FILE command to redirect a
database or database-access file to a different file because that file can be
purged easily.
The DBRECOV utility is not included in the discussion above because it is an exception. With
DBRECOV, MPE/iX FILE commands are permissible and do not require a logon to the same
group and account as the log file. However, DBRECOV must be invoked on the system where
the database resides.
You can operate the database utilities if you are the database creator or if you know the
maintenance word. If no maintenance word is defined, only the database creator can
execute the database utilities. The exception to this rule is that a user with system