Define a varialbe mostly for deployment-specific purpose.
A report can have deployment-specific dependencies. For example, report developers ofen use a test database during development, but target a production database once the report is deployed online. Or, an OEM company may use a different company name in report titiles for each of their customers.
Experiences suggest that changing the report design to reflect these changes is both tedious and error-prone. We need a simple solution. Therefore, BIRT provides configuration variables. A configuration variable is simply a name/value pair very similar to an environment variable in Unix. Indeed, configuration variables include environment variables, along with BIRT-specific values.
Name of the variable.
A configuration variable has a unique and required name, report use the name to references a configuration variable.
Value of the configuration variable.
Value of the configuration variable, report can override this value to provide a default value.