DB2 10.5 for Linux, UNIX, and Windows

Adjusting the log space size in upgraded databases

You need to set the appropriate size for log files since it is one of the important factors in tuning your DB2® server. Also, if you increased the log files sizes as a pre-upgrade task, you can restore additional free space to your DB2 server.

Before you begin

To increase the size of table spaces and log space, you must have SYSCTRL or SYSADM authority.

Restrictions

On a partitioned database environment, you must adjust the log space size on the catalog database partition server.

Procedure

  1. Connect to the database that you upgraded:
       db2 CONNECT TO sample
    where sample is the database name.
  2. Restore your log file size settings to the values you had before upgrade:
       db2 UPDATE DB CFG FOR sample using LOGSECOND previous-value
    where previous-value is the setting that you save before upgrade and sample is the database name. In the pre-upgrade task, only the logprimary and the logsecond parameters were changed. If you change the setting for the logfilsiz parameter, you should restore the previous value.
    If you enabled infinite active logging, disable it by running the following commands:
       db2 UPDATE DB CFG FOR sample using LOGARCHMETH1 previous-value
       db2 UPDATE DB CFG FOR sample using LOGSECOND previous-value
    where previous-value is the setting that you save before upgrade and sample is the database name.
  3. To support larger log record headers, increase the log space setting, by approximately 10% - 15% over what you used for DB2 Version 9.7.
  4. To support larger log record headers, increase the softmax parameter by 10% - 15% over what you used for DB2 Version 9.7.
       db2 UPDATE DB CFG FOR sample using SOFTMAX 1.15 * previous-value
    Important: The softmax database configuration parameter is deprecated is deprecated in Version 10.5 and might be removed in a future release. For more information, see Some database configuration parameters are deprecated.
  5. Double the value for the logbufsz parameter:
       db2 UPDATE DB CFG FOR sample using LOGBUFSZ 2 * previous-value
  6. Disconnect from the database that you upgraded:
       db2 CONNECT RESET
    logfilsiz changes take effect only when the database is reactivated. All applications must first disconnect from the database then deactivate and activate the database again.