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SAP MaxDB Database Analyzer Parameter Check

As bad performance could be caused by wrong parameter settings, you should check the database configuration first before you start a performance analysis.

General Information
How to Execute the Parameter Check
Parameter Check Output

General Information

SAP MaxDB offers a check tool for database kernel parameter settings. This check is embedded into the Database Analyzer. The parameter check tool is used to check whether the configuration of your SAP MaxDB, SAP liveCache, OneDB or BW system corresponds to the current SAP recommendations.In general the parameter recommendations which are described in the database parameter notes (for example SAP MaxDB Version 7.9: 1346964, SAP MaxDB Version 7.8: 1308217) are checked.

The parameter check should be executed after each upgrade to a new SAP MaxDB/liveCache version. Different recommendations may be relevant for different database versions.

The parameter check tool uses a special Database Analyzer configuration file dbanalyzer_InstanceParameterCheck.cfg.

This special configuration file is attached to note 1111426 (SAP MaxDB Database Parameter Check File). As this file is regulary updated, you must download it again before each check. This file can be stored in a temporary directory - e.g. /tmp
Use sapcar -xvf DbanalyzerParamCheck.sar to extract the configuration file dbanalyzer_instanceParameterCheck.cfg
Do not replace the original database analyzer config file with the new one!

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How to Execute the Parameter Check

The database instance must be in operational state ONLINE when you start the parameter check tool.
Perform the automatic check as database system administrator (e.g. superdba).

dbanalyzer -d <database_name> -u <database_system_administrator>,<password> -f c:\tmp\dbanalyzer_instanceParametercheck.cfg -o c:\tmp\param_check -i -c 1 -t 1,1 -n <computer_name>

-i the output directory will be cleaned up
-c output will be send to screen as well
-t only 1 snapshot in an interval of one second

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Parameter Check Output

Analyze the screen output or the file /tmp/param_check/<YYYYMMDD>/DBAN.prt. Important are all messages that are marked with "* W1 to * W3"

The following checks are executed:

  • general parameters
  • parameters which influence the I/O performance
  • optimizer parameters
  • special liveCache parameters

Additional checks

  • do corrupt indexes exist?
  • is the database kernel trace activated?
  • do tables exist which do not have any file directory counters?
  • is logging activated and autooverwrite deactivated?
  • does the size of the IO Buffer Cache correspond to the SAP recommendation, which is 2% of the configured volume size for UNICODE systems and 1% for NON-UNICODE systems?

If there are database parameter settings which differ from the recommendation you can use Database Studio, transaction DBACOCKPIT/DB50 or Database Manager CLI to change the database parameter setting.

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