Installation and Initial Configuration 1-11

OnLine Configuration Files

OnLine Configuration Files
Youare not limited to just one configuration file. You can createand manage
multipleOnLine configuration files, and each file can contain a unique set of
configurationparameter 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 variableINFOR-
MIXDIR. One of the files loaded during installation istbconfig.std, which is
locatedin the directory $INFORMIXDIR/etc. 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.
TheOnLine environment variable TBCONFIG specifies the name of the UNIX
file(which must be located in the directory $INFORMIXDIR/etc) that is read
asinput to either the disk-space or shared-memory initialization procedure.
TheTBCONFIG environment variable enables you to create and maintain
multiple configuration files, each with different values. As userinformix,
youcan initialize OnLine shared memory with a different set of configuration
parameters by resetting the value ofTBCONFIG.
The default value of TBCONFIG is defined astbconfig. When you first load
the OnLine 5.x software, the filetbconfig does not exist. The tbconfig file is
createdfor you the first time that you initialize OnLine. If you initialize from
withinDB-Monitor, the tbconfig file contains the parameter values entered as
part of initialization. If you initialize from the command line, using the
OnLineutility tbinit, the tbconfig file contains default values obtained from
tbconfig.std.
You set the value ofTBCONFIG when you define the environment variables
as one of your last tasks during installation.
Youcan modify the configuration file from within DB-Monitor while OnLine
isonline. The changes you make are written immediately to the file specified
asTBCONFIG.IfTBCONFIGis not specified, OnLine modifies the file tbconfig.
Buteven though the values in the file change, most changes to the parameter
valuesdo 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.