Object identification
Follow this information to learn about the complexity of using multiple databases on a single system and what different parameters mean to CL commands.
Because the existence of an independent disk pool on a system means that multiple databases exist on a single system, identifying an object is more complex than it is on a system with only a single system database. When multiple databases exist, it is possible to duplicate the names of libraries and objects in separate databases. The library name and object name do not necessarily uniquely identify an object. There will be times when you also need to know the name of the independent disk pool. The name of the independent disk pool and its database are, by default, the same. However, they do not necessarily have to match. A database name can be up to 18 characters long, while an independent disk pool name can be up to 10 characters long.
While the same library name can exist in two different disk pool groups, libraries cannot have the same name in the system disk pool as in an independent disk pool.
Control language (CL) commands
When using control language (CL) commands that support specification of *ALL or *ALLUSR for the libraries to be searched, the system will typically interpret this to mean "all (user) libraries in your current library namespace" rather than "all (user) libraries on the system." Some commands may interpret *ALL or *ALLUSR differently, so it is important to check the command documentation.If you used the Display Object Description (DSPOBJD) command, certain system libraries, like QSYS, may appear multiple times if the command is showing information for both the system disk pool and one or more independent disk pools.