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Quick Beginnings for DB2 Extended Enterprise Edition for UNIX

DB2 Registry Values and Environment Variables

The following subset of the DB2 registry values and environment variables are those that you may need to know about to get up and running. Each has a brief description; some may not apply to your environment.

You can view a list of all supported variables for your platform. On all operating systems except Windows 3.1, enter the following db2set command:

   db2set -lr
Note:Windows 3.1 clients define environment variables in the file db2.ini. See "Setting Your Environment on Windows 3.x" for details.

Parameter Operating System Values Description
DB2ACCOUNT All Default: (not set) The accounting string that is sent to the remote host. Refer to the DB2 Connect User's Guide for details.
DB2CODEPAGE All Default: derived from the language ID, as specified by the operating system. Specifies the code page of the data presented to DB2 for database client application. The user should not set db2codepage unless explicitly stated in DB2 documents, or asked to do so by DB2 service. Setting db2codepage to a value not supported by the operating system can produce unexpected results. Normally, you do not need to set db2codepage because DB2 automatically derives the code page information from the operating system.
DB2COUNTRY All Default: derived from the language ID, as specified by the operating system. Specifies the country code of the client application, which influences date and time formats.
DB2DBDFT All Default: (not set) Specifies the database alias name of the database that will be implicitly connected to when applications are started and no implicit connect has been done. This keyword is ignored if it is not set.
DB2DISCOVERYTIME OS/2, Windows 95, and Windows NT Default=40 seconds, minimum=20 seconds Specifies the amount of time that SEARCH discovery will search for DB2 systems.
DB2ENVLIST UNIX Default: (not set) Lists specific variable names for either stored procedures or user defined functions. By default, the db2start command filters out all user environment variables except those prefixed with DB2 or db2. If specific environment variables must be passed to either stored procedures or user defined functions, you can list the variable names in the db2envlist environment variable. Separate each variable name by one or more spaces. DB2 constructs its own PATH and LIBPATH, so if PATH or LIBPATH is specified in db2envlist, the actual value of the variable name is appended to the end of the DB2-constructed value. For example, LIBPATH becomes DB2LIBPATH.
DB2INCLUDE All Default=current directory Specifies a path to be used during the processing of the SQL INCLUDE text-file statement during DB2 PREP processing. It provides a list of directories where the INCLUDE file might be found. Refer to the Embedded SQL Programming Guide for descriptions of how db2include is used in the different precompiled languages.
DB2INSTDEF OS/2, Windows 95 and Windows NT Default=DB2 (on OS/2, Windows 95 and Windows NT) Sets the value to be used if DB2INSTANCE is not defined.
DB2LIBPATH UNIX Default: (not set) Specifies the value of LIBPATH in the db2libpath environment variable. On UNIX operating systems, the value of LIBPATH cannot be inherited between parent and child processes if the user ID has changed. Since the db2start executable is owned by root and its execute permissions are setuid to root, DB2 cannot inherit the LIBPATH settings of end users. If you list the variable name, LIBPATH, in the db2envlist environment variable, you must also specify the value of LIBPATH in the db2libpath registry value. The db2start executable will then read the value of db2libpath and append this value to the end of the DB2-constructed LIBPATH.
DB2NTMEMSIZE Windows NT Default=(not set) Used to override the upper limit of the DB2 shared memory segment.
DB2OPTIONS All except Windows 3.1 and Macintosh Default=null Sets command line processor options.
DB2SLOGON Windows 3.1 Default: NO Enables a secure logon in DB2 for Windows 3.1. If db2slogon=YES DB2 does not write user IDs and passwords to a file, but instead uses a segment of memory to maintain them. When db2slogon is enabled, the user must logon each time Windows 3.1 is started.
DB2TIMEOUT Windows 3.1 and Macintosh Default: (not set) Used to control the timeout period for Windows 3.1 and Macintosh clients during long SQL queries. After the timeout period has expired a dialog box pops up asking if the query should be interrupted or allowed to continue. The minimum value for this variable is 30 seconds. If db2timeout is set to a value between 1 and 30, the default minimum value will be used. If db2timeout is set to a value of 0, or a negative value, the timeout feature is disabled. This feature is disabled by default.
DB2TRACENAME Windows 3.1 and Macintosh Windows 3.1 Default=DB2WIN.TRC

Macintosh Default=DB2MAC.TRC

On Windows 3.1 and Macintosh, specifies the name of the file where trace information is stored. The default is on Windows 3.1 is db2tracename=DB2WIN.TRC, and is saved in your current instance directory (for example, \sqllib\db2). The default on Macintosh is db2tracename=DB2MAC.TRC. We strongly recommend that you specify the full path name when naming the trace file.
DB2TRACEON Windows 3.1 and Macintosh Default=N, values: Y, N On Windows 3.1 and Macintosh, turns trace on to provide information to IBM in case of a problem. (It is not recommended that you turn trace on unless you encounter a problem you cannot resolve.) Refer to the Troubleshooting Guide for information on using the trace facility with DB2 Client Application Enabler.
DB2TRCFLUSH Windows 3.1 and Macintosh Default=N, values: Y, N On Windows 3.1 and Macintosh, db2trcflush can be used in conjunction with db2traceon=Y. db2trcflush=Y will cause each trace record to be written immediately into the trace file. Setting this will slow down your DB2 system considerably, so the default setting is db2trcflush=N. This setting is useful in cases where an application hangs the system and therefore needs to be rebooted. Setting this keyword guarantees that the trace file and trace entries are not lost by the reboot.
Default=1, values: 1 - 32767 Specifies the number of system errors to trace before the client turns off tracing. The default value traces one system error, after which, trace is turned off.
DB2YIELD Windows 3.1 Default=N, values: Y, N Specifies the behavior of the Windows 3.1 client while communicating with a remote server. When N is set, the client will not yield the CPU to other Windows 3.1 applications, and the Windows environment is halted while the client application is communicating with the remote server. You must wait for the communications operation to complete before you can resume any other tasks. When set to Y, your system functions as normal. It is recommended that you try to run your application with db2yield=YES. If your system crashes, you will need to set db2yield=NO. For application development, ensure your application is written to accept and handle Windows messages while waiting for a communications operation to complete.
System Environment
DB2INSTANCE All Default=db2instdef on OS/2, Windows 95, and Windows NT The environment variable used to specify the instance that is active by default. On UNIX, users must set the environment variable DB2INSTANCE.
DB2INSTPROF OS/2, Windows 95, and Windows NT
The environment variable used to specify the location of the instance directory on OS/2, Windows 95 and Windows NT operating systems, if different than DB2PATH.
DB2PATH OS/2, Windows 95 and Windows NT
The environment variable used to specify the directory where the product is installed on OS/2, Windows 95 and Windows NT operating systems.
DB2COMM All, server only Default= null, values: any combination of APPC,IPXSPX, TCPIP Specifies the communication managers that are started when the database manager is started. If this is not set, no DB2 communications managers are started at the server.
DCE Directories
Specifies a temporary override of the DIR_PATH_NAME parameter value in the database manager configuration file. If a directory server is used and the target of a CONNECT statement or ATTACH command is not explicitly cataloged, then the target is concatenated with db2dirpathname (if specified) to form the fully qualified DCE name.
Note:The db2dirpathname value has no effect on the instance's global name, which is always identified by the database manager configuration parameters DIR_PATH_NAME and DIR_OBJ_NAME.
Specifies a temporary override of the DFT_CLIENT_COMM parameter value in the database manager configuration file. If both DFT_CLIENT_COMM and db2clientcomm are not specified, then the first protocol found in the object is used. If either one or both of them are specified, then only the first matching protocol will be used. In either case, no retry is attempted if the first connect fails.
DB2ROUTE OS/2 and UNIX Default Specifies the name of the Routing Information Object the client uses when it connects to a database with a different database protocol. The db2route value overrides the ROUTE_OBJ_NAME parameter value in the database manager configuration file.
Note: There are three registry values that are related to ADSM:




Refer to the Administration Guide for information about ADSM and these values.

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