IBM 000-8697 Manual Do Utilizador

Installation and Initial Configuration

You are not limited to just one configuration file. You can create and manage
multiple OnLine configuration files, and each file can contain a unique set of
configuration parameter values. This section explains how multiple configu-
ration files are created and managed.

As part of OnLine 5.x installation, the product software is loaded into the
Informix product directory, specified as the environment variable

INFOR-

MIXDIR

. One of the files loaded during installation is tbconfig.std, which is

located in the directory $

. The tbconfig.std file contains the

default values for the configuration parameters and serves as the template
for all other configuration files that you create.

The OnLine environment variable

TBCONFIG

specifies the name of the

UNIX

file (which must be located in the directory $

) that is read

as input to either the disk-space or shared-memory initialization procedure.
The

TBCONFIG

 environment variable enables you to create and maintain

multiple configuration files, each with different values. As user informix,
you can initialize OnLine shared memory with a different set of configuration
parameters by resetting the value of

TBCONFIG

.

The default value of

TBCONFIG

 is defined as tbconfig. When you first load

the OnLine 5.x software, the file tbconfig does not exist. The tbconfig file is
created for you the first time that you initialize OnLine. If you initialize from
within

DB-M

onitor, the tbconfig file contains the parameter values entered as

part of initialization. If you initialize from the command line, using the
OnLine utility tbinit, the tbconfig file contains default values obtained from
tbconfig.std

.

You set the value of

TBCONFIG

 when you define the environment variables

as one of your last tasks during installation.

You can modify the configuration file from within

DB-M

onitor while OnLine

is online. The changes you make are written immediately to the file specified
as

TBCONFIG

. If

TBCONFIG

is not specified, OnLine modifies the file tbconfig.

But even though the values in the file change, most changes to the parameter
values do not take effect until you reinitialize OnLine shared memory. Until
you take this step, it is possible that the values in the file specified as

TBCONFIG

 do not match the values in your current, effective configuration.