Once objects are no longer used, you should drop them to save system resources.
To drop an object:
Note: Dropping an object that contains another object, such as a schema that contains a table, will result in the contained objects being dropped also. Objects that are related to the dropped objects, such as an alias for a table, will be located and you will be given the option of dropping those objects as well.
To drop a journal receiver, it must not be attached to a journal.
To drop a journal, you must stop journaling for each table that is attached to the journal.
Dropping a journal does not remove the receivers from the schema.