iX V6.5 (30391-90011)

Chapter 7 357

Logging and Recovery

DBRECOV Commands Used with Roll-Forward and Roll-Back Recovery

DBRECOV Commands Used with Roll-Forward and

Roll-Back Recovery

The following DBRECOV commands are used for either roll-forward or roll-back recovery:

CONTROL Speciﬁes the conditions for recovery.

FILE Sorts the log ﬁle by individual users and/or user identiﬁers, and designates

an MPE/iX ﬁle as the destination for each user's log records.

PRINT Displays information before you actually initiate recovery with the >RUN

command.

RECOVER Designates the name of a database to be recovered using roll-forward

recovery.

ROLLBACK Designates the name of a database to be rolled back.

RUN Initiates recovery of the speciﬁed database.

These commands are discussed below; refer to chapter 8 for more detailed information.

CONTROL Command

The >CONTROL command is used to specify the conditions for recovery. If the >CONTROL

command is not issued, these four default conditions must be met for recovery to succeed:

• The database time stamp in the root ﬁle must correspond with the time stamp in each

DBOPEN log ﬁle record.

• The DBSTORE ﬂag must be set in the database root ﬁle.

• No errors are allowed in job (batch) execution.

• Transactions that are incomplete due to program aborts are recovered.

The >CONTROL command can be used to override these conditions. Each override option can

be negated by specifying its default option, and vice versa, as follows:

Option Default Option

NOMDBX MDBX

NOSTAMP STAMP

NOSTORE STORE

NOABORTS ABORTS

MODE4 MODEX

STATS NOSTATS

ERRORS=nnnn

ERRORS=0 (job) or ERRORS=30,000 (session)

STOPTIME=dateX timeX STOPTIME=dateY timeY

EOF=pppp EOF=qqqq