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Database maintenance

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Database maintenance

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IBM brand Intelligent Transportation IBM Traffic Information Hub Version 1.0.1

Database maintenance

When the IBM? Intelligent Transportation solutionis running large amounts of traffic data are collected and generated.To optimize the performance of the solution ensure that the databasesof the IBM Traffic Information Hub are maintainedon a regular basis.

To prevent performance issues implement a data maintenance strategyto remove obsolete data periodically reorganize database tablesand maintain current database table statistics. A regularly scheduledmaintenance plan is essential for maintaining peak performance ofyour system.

Perform the following database maintenance activities at leastonce a week:
REORGCHK
Use the REORGCHK command to update the statisticsfor all objects in the database and determine which tables and indexesmust be reorganized. The REORGCHK command calculatesstatistics on the database to determine whether tables or indexesor both need to be reorganized or cleaned up. The REORGCHK commandoutputs list of all table and index objects in the database. Objectswith an asterisk (*) in the REORG column mightneed to be reorganized.
REORG
Use the REORG command to reorganize a databasetable by compacting information and reconstructing the rows to eliminatefragmented data. After you use the REORGCHK commandto identify the database tables or indexes to be reorganized youmust explicitly invoke the REORG command for eachobject. Tables or indexes identified by REORGCHK arenot automatically reorganized.
Feature available when the optional transportation prediction component is installed If you have installed the optional transportation prediction feature and yourtransportation network has at least 2000 links then for optimum performanceyou will need to run the REORG command every dayon the following database tables:
  • tptool.LINK_REPORT
  • tptool.LINK_STATS
  • tptool.LINK_FORECAST
  • tmdd.LINK_STATUS
  • datex_II.TRAFFICSPEED
  • datex_II.TRAFFICFLOW
RUNSTATS
Use the RUNSTATS command to update statisticson a daily or weekly basis. It is also recommended that you updatethe statistics after schema changes a massive update or increasedload such as refreshing the catalog. The statistics updated by the RUNSTATS commandare used by the optimizer when determining access paths to the datatherefore inaccurate statistics can result in decreased database efficiency.
REBIND
After running RUNSTATS on the database tablesrebind your applications to take advantage of the latest statisticaldata. Rebinding ensures that DB2? isusing the best access plan. Perform a REBIND afterrunning RUNSTATS as part of you normal databasemaintenance procedures.
Note: If a package is already in use the db2rbind commandcannot rebind a package.

Some of the database maintenance activities might cause some performancedegradation and locking while they are being executed. Perform databasemaintenance during a period of low or minimal usage of the IBM Intelligent Transportation andthe IBM Intelligent Operations Center.

For more information about the database maintenance commands andhow they work see the DB2 InformationCenter.

Parent topic: Maintaining the database
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Document Information

Modified date:
08 December 2018

UID

ibm10757333

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