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

Chapter 7 341
Logging and Recovery
Logging Maintenance
To illustrate another example when TurboSTORE/iX 7x24 True-Online Backup (with
ONLINE=START or ONLINE=END option) was used to back up the database, assume
that the log file in use during backup was LOGF041. If a database needs to be recovered
and the logging cycle is currently writing to LOGF065, DBRECOV will begin recovery with
LOGF041 (following the backup) and will continue until LOGF065.
The resulting impact on recovery time is why serious consideration should be given to the
logging cycle. The shorter the logging cycle is, the shorter the recovery time.
Ending the Logging Maintenance Cycle
At the end of the specified maintenance cycle (for example, the end of day) do the following:
1. If you plan on using TurboSTORE/iX 7x24 True-Online Backup (with ONLINE=START
or ONLINE=END option), omit this step. Otherwise, stop the logging process at the
console with the LOG command.
2. If you plan on using TurboSTORE/iX 7x24 True-Online Backup (with ONLINE=START
or ONLINE=END option) when the database is
open for access , you must omit this
step. In other cases, including when using TurboSTORE/iX 7x24 True-Online Backup
(with ONLINE=START or ONLINE=END option) when the
database is closed ,
run DBUTIL and do the following tasks:
• Disable access to the database.
• Enable recovery of the database.
3. Store a database backup copy (required for roll-forward recovery) with DBSTORE or
TurboSTORE/iX 7x24 True-Online Backup (with ONLINE=START or ONLINE=END
option).
Example
Example when using DBSTORE:
:LOG ORDERLOG,STOP
:RUN DBUTIL.PUB.SYS
.
.
.
>>DISABLE ORDERS FOR ACCESS
Access is Disabled
>>ENABLE ORDERS FOR RECOVERY
Recovery is Enabled
>>EXIT
END OF PROGRAM
:RUN DBSTORE.PUB.SYS
WHICH DATA BASE? ORDERS
DATA BASE STORED
END OF PROGRAM
Example when using TurboSTORE/iX 7x24 True-Online Backup (with ONLINE=START
or ONLINE=END option) and database is open for access: