Database manager parameters are stored in a file named db2systm. This file is created when the instance of the database manager is created. In UNIX-based environments, this file can be found in the sqllib subdirectory for the instance of the database manager. In all other environments, the default location of this file is the instance subdirectory of the sqllib directory. If the DB2INSTPROF variable is set, the file is in the instance subdirectory of the directory specified by the DB2INSTPROF variable.
In a partitioned database environment, this file resides on a shared file system so that all database partition servers have access to the same file. The configuration of the database manager is the same on all database partition servers.
Most of the parameters either affect the amount of system resources that will be allocated to a single instance of the database manager, or they configure the setup of the database manager and the different communications subsystems based on environmental considerations. In addition, there are other parameters that serve informative purposes only and cannot be changed. All of these parameters have global applicability independent of any single database stored under that instance of the database manager.
The db2systm file cannot be directly edited. It can only be changed or viewed using a supplied API or by a tool which calls that API.
Attention: If you edit the file using a method other than those provided by the product, you may make your system unusable. We strongly recommend that you do not change this file using methods other than those documented and supported by DB2.
You may use one of the following three methods to reset, update, and view the database manager configuration parameters:
After changing the parameters, the database manager must be stopped (db2stop) and then restarted (db2start) for the new parameter values to take effect. For clients, changes in the database manager configuration parameters take effect the next time the client connects to a server. While new parameter values are not immediately effective, viewing the parameter settings will always show the latest updates.
Note: | You do not need to restart the database manager if you update the value of the dft_monswitches parameter; this parameter is updated automatically when you change its value. |
The following table lists the parameters in the database manager configuration file for database servers. When changing the database manager configuration parameters, consider the detailed information for each parameter. Specific operating environment information including defaults is part of each parameter description.
The column "Performance Impact" in the following table provides an indication of the relative importance of each parameter as it relates to system performance. It is impossible for this column to apply accurately to all environments; you should view this information as a generalization.
Table 46. Configurable Database Manager Configuration Parameters
Table 47. Informational Database Manager Configuration Parameters
Parameter | Additional Information |
---|---|
nodetype | "Machine Node Type (nodetype)" |
release | "Configuration File Release Level (release)" |