drop user; just delete the user,
drop user × × cascade; will delete the user name and view all the tables.
user
Specify the user to be dropped. Oracle Database does not drop users whose schemas contain objects unless you specify CASCADE or unless you first explicitly drop the user's objects.
CASCADE
Specify CASCADE to drop all objects in the user's schema before dropping the user. You must specify this clause to drop a user whose schema contains any objects.
Parameter can be deleted using the cascade of all the user objects. To note the following:
1 If the user's schema contains tables, then Oracle Database drops the tables and automatically drops any referential integrity constraints on tables in other schemas that refer to primary and unique keys on these tables.
If the user's schema in the table, then delete the table automatically deleted when the table associated with the primary key and foreign key.
2 If this clause results in tables being dropped, then the database also drops all domain indexes created on columns of those tables and invokes appropriate drop routines.
If the user's schema in the table, then delete the table automatically deleted when the index associated with the table.
3 Oracle Database invalidates, but does not drop, the following objects in other schemas:
Delete a user, the following objects in the other user will not be deleted in will only be set to invalid
1 Views or synonyms for objects in the dropped user's schema
Views, synonyms
2 Stored procedures, functions, or packages that query objects in the dropped user's schema
Stored procedures, functions, packages
4 Oracle Database does not drop materialized views in other schemas that are based on tables in the dropped user's schema. However, because the base tables no longer exist, the materialized views in the other schemas can no longer be refreshed.
Other users to create user-based materialized views are deleted are not deleted, but can not be refreshed.
5 Oracle Database drops all triggers in the user's schema.
User mode to delete all triggers
6 Oracle Database does not drop roles created by the user.
Deleted user created the other user will not be deleted
If the urer no tables and other objects you just created, you can use the drop user command to remove, or to use the drop user cascade command to delete, then the user will be deleted along with the object.
Transfer from http://hi.baidu.com/amingsc/blog/item/9aa3fc242c0c51094d088d56.html