Using Libraries

The following principles should be applied for the use of libraries under OS/400 and the organization of a development environment on IBM i:

For a given application, separate the live data files, the application objects, and the source files into different libraries. The national language dependent objects, such as commands and panel groups, may also need to be separated from the other application objects.
For each application, use a separate set of libraries; very large libraries are inefficient to use.
Avoid having cross-library dependencies; for instance logical files based on physical files in different libraries, or journal receivers attached to journals in another library.
Keep development separate from the live systems. Separate user profiles, using object ownership and authorization to enforce this.
Note: For more information on security standards, refer to the section, User Profile and Security Standards, in this guide.
Make the live and the test environments as similar as possible.
Establish libraries to be able to determine an object’s type, and its development status (new, under test, live), by which library it is in.
Use software tools for the routine housekeeping tasks involved in implementing new objects.
Avoid explicit references to library names in code.
Avoid qualified references to libraries. Do not hard code references to library names as it means that the library list cannot be used to find objects.