IBM Traveler database maintenance for HA deployments
The IBM Traveler server has the ability to perform basic database maintenance tasks including reorganizing indexes and running statistics.
This function was designed as a convenience for customers to perform regular database
maintenance. Customers that already have a successful database maintenance routine can continue to
perform their own maintenance instead of using DBMaint. DBMaint
reorganizes the IBM Traveler indexes using an online operation. Since the task is online there
should not be any disturbance to the IBM Traveler service, but it is recommended to run during off
peak hours. We recommend performing online index maintenance once a week during non-peak hours and
offline maintenance about once a month.
For DB2, execute the command reorg indexes all for table <TABLE> allow write access
CLEANUP ONLY. For more information about this command and performing REORG
commands for DB2, refer to the information on the REORG INDEXES/TABLE command in
this topic.
For SQL Server, execute the query ALTER INDEX ALL ON <SCHEMA>.<TABLE>
REORGANIZE. For more information about this query and maintaining indexes please refer to
the Reorganize and Rebuild Indexes section of this
link.
Performing database maintenance using IBM Traveler
Performing the tell command DBMaint run will immediately execute an online
reorganization of the IBM Traveler table's indexes. It will also run statistics on all indexes in
the IBM Traveler database. This command is an online operation that should not affect the IBM
Traveler service. We recommend that this maintenance is performed during non-peak hours.
Configuring automatic database maintenance using IBM Traveler
The IBM Traveler server can automatically perform maintenance on its enterprise database using
the tell command DBMaint. In order for IBM Traveler to automatically perform
maintenance, both the Time and Interval subcommands of
DBMaint must be set. The time is the time of day in which the maintenance will
execute. The interval is the number of days in between maintenance executions. If automatic
maintenance needs to be run on a specific day of the week, then the tell command
Day can be set. After which, the subsequent database maintenance times will be
based off of the configured interval. Setting Auto to On will
automatically schedule maintenance. If the maintenance should be rescheduled, then setting
Auto to On will reschedule maintenance based on the set time,
interval and day. To check when the next maintenance is scheduled for, use the tell command
Show. This outputs all available information about the DBMaint configuration,
including when the last maintenance was executed and when the next database maintenance is
scheduled.
IBM Traveler can also check the database's fragmentation level against a configured threshold.
This is done with the Fragmentation tell command. If there are more indexes
fragmented than the threshold is configured for, then defragmentation is recommended. The number of
indexes needed to be fragmented to be above the fragmentation threshold can be configured using the
tell command Set Indexes. For Microsoft SQL Server, the tell command Set
Percent defines a percentage of fragmentation in which an index must be above to be
considered fragmented. For example, IBM Traveler defaults the percent to thirty. If an index is
above thirty percent fragmented, then IBM Traveler considers it above the threshold. For DB2, the
tell command Set Functions will define the number of functions (out of four) needed
to consider an index fragmented above the threshold. IBM Traveler defaults to requiring two of these
functions to determine if an index is fragmented. Automatic maintenance will check the fragmentation
level before executing if the Threshold tell command is set to
On.