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

Chapter 7 359
Logging and Recovery
DBRECOV Commands Used with Roll-Forward and Roll-Back Recovery
the intrinsics DBOPEN and DBCLOSE. Rmode refers to transactions that recovered
successfully; fmode refers to transactions that failed to be recovered. Refer to the DBRECOV
>FILE command for details of operation.
PRINT Command
The >PRINT command is an option used to display information before actually initiating
recovery with the >RUN command. If DBTABLE is specified in the >PRINT command, the
names of the databases specified for recovery by >RECOVER commands are returned. Note
that no statistics are returned with the >PRINT DBTABLE command, because none exist
before the log file is read. If you need these statistics without actually performing the
recovery, use >CONTROL STATS to display this information. If FILETABLE is specified in the
>PRINT command, file references, user references, fmodes and rmodes specified by >FILE
commands are returned. These tables, along with statistics, are also printed when
recovery is complete.
RECOVER Command
The >RECOVER command designates the name of a database to be recovered using
roll-forward recovery. If more than one database has logged to the same log file, they can be
recovered concurrently by entering the database names separated by a comma.
If the database copy was stored with a program other than DBSTORE or True-Online
Backup (for example, MPE/iX STORE without ONLINE=START or ONLINE=END option),
the DBSTORE flag will not have been set in the database root file.
If you are sure you have restored the correct, unmodified version of the database, and wish
to use it for recovery, the >CONTROL NOSTORE option must be entered before the >RECOVER
command can succeed (refer to the discussion of >CONTROL in chapter 8).
Other conditions necessary for the success of the >RECOVER command include:
• The database must be accessible to you from your logon group and account.
• The log identifier must not have been altered since the log file was generated (see "Step
6--Setting the Log Identifier," earlier in this chapter).
• The database must be enabled for recovery.
• All databases specified for recovery must contain the same log identifier.
• You must be the database creator, or know the database maintenance word.
• You must either be the creator of the log identifier, or have system manager (SM) or
operator (OP) capability.
• No other users are accessing the database. The database may be concurrently accessed
by users when the >CONTROL command is specified with the MODE4 option. Refer to
the >CONTROL MODE4 command discussed with DBRECOV in the next chapter.
If the >RECOVER command succeeds, recovery can be initiated by typing the >RUN
command.