This parameter specifies the maximum number of file handles that can be open for each database agent. If opening a file causes this value to be exceeded, some files in use by this agent are closed. If maxfilop is too small, the overhead of opening and closing files so as not to exceed this limit will become excessive and may degrade performance.
Both SMS table spaces and DMS table space file containers are treated as files in the database manager's interaction with the operating system, and file handles are required. More files are generally used by SMS table spaces compared to the number of containers used for a DMS file table space. Therefore, if you are using SMS table spaces, you will need a larger value for this parameter compared to what you would require for DMS file table spaces.
You can also use this parameter to ensure that the overall total of file handles used by the database manager does not exceed the operating system limit by limiting the number of handles per agent to a specific number; the actual number will vary depending on the number of agents running concurrently.