By default, Oracle will run some maintance jobs every night. If you don't want to run those jobs, you can just disable them.
Query the automatic jobs using the SQL statement below,
select * from DBA_AUTOTASK_CLIENT
You would normally see the following 3 jobs:
(1) auto optimizer stats collection
(2) auto space advisor
(3) sql tuning advisor
You can disable them by running the following script,
BEGIN DBMS_AUTO_TASK_ADMIN.disable( client_name => 'auto optimizer stats collection', operation => NULL, window_name => NULL); end; / BEGIN DBMS_AUTO_TASK_ADMIN.disable( client_name => 'auto space advisor', operation => NULL,window_name => NULL); end; / BEGIN DBMS_AUTO_TASK_ADMIN.disable( client_name => 'sql tuning advisor', operation => NULL,window_name => NULL); end; / commit;