How to check the general health of the system ?

How to check the general health of the system ?

SELECT file_id,
       tablespace_name,
       file_name,
       status
FROM   sys.dba_data_files;

SELECT file#,
       name,
       status,
       enabled
FROM   v$datafile;

SELECT *
FROM   v$backup;

SELECT *
FROM   v$recovery_status;

SELECT *
FROM   v$recover_file;

SELECT *
FROM   v$recovery_file_status;

SELECT *
FROM   v$recovery_log;

SELECT username,
       command,
       status,
       module
FROM   v$session;