CONFIG.D

A configuration file can be used to control internal buffer pool configurations, variable pool configurations, and to establish certain MODEs and/or preset variables.

This file must be named CONFIG.D and must exist in the same folder as Thunderbolt. (An exception to this is discussed further below.) This file must exist prior to invoking Thunderbolt as, if it exists and is in the right place, it is used during the time Thunderbolt is loading itself into memory and configuring it-self.

The configuration file is not required; it is used to override defaults. But some MODEs you may want to use require that they must be in the configuration file, so in that case you must have one.

Creating the CONFIG.D File

You can use any pure ASCII text editor to create the CONFIG.D file. If you use the Thunderbolt Editor you must use the O option on the FILE command so that the file will be saved as pure text and not in graphical format.

Statements in the Configuration File

                SVAR n  -Specifies a new maximum number of string variables
                NVAR n -Specifies a new maximum number of numeric variables
                SET                         -Any legitimate SET command
                CALC                     -Any legitimate CALC command
                MODE                    -Any legitimate MODE command
                BUFFERS              -Specifies a configuration for the basic buffer pool

The SVAR and NVAR statements, if used, must occur first. That is, they must appear before any other statements in a CONFIG.D file. The default number of variables allowed of both types is 400, you can increase either or both of these up to 2000.

The default BUFFERS configuration is 32 60 6. The first number is the number of basic data buffers in the pool, the second controls the size of sort blocks, and the third controls the number of sort blocks. We have determined that these numbers provide optimum performance. If you are tight on memory you can use a BUFFERS statement to reduce memory requirements, (e.g., BUFFERS 20 30 3 ), but reduce it no further than that. The cost of such a reduction is that it will degrade sort times by about 20 percent.

A sample CONFIG.D file might look like:

                SVAR 500
                NVAR 500
                MODE CBUFF 32768 20

See MODE CBUFF for a description of the last statement.

Placement of the CONFIG.D File

The CONFIG.D file does not have to be named CONFIG.D and it does not have to be placed in the same folder as Thunderbolt. These are just the default name and placement. If you want separate config files for separate applications, here is how:

There is an environment variable named WINDDL_CONFIG that can be set with the full path name of your CONFIG file prior to executing Thunderbolt. If this environment variable exists, Thunderbolt picks up the name and location of the config file from there rather than from its own folder.
Remember, you must specify the full pathfile name.