su - oracle
sqlplus /nolog
sqlplus user/password [as sysdba]

select * from v$flash_recovery_area_usage;
select * from v$recovery_file_dest;
select space_limit/1024/1024/1024, space_used/1024/1024/1024, space_reclaimable,number_of_files from v$recovery_file_dest;

rman target /
# archive 
# 确认归档模式的状态  
ARCHIVE LOG LIST;
DELETE ARCHIVELOG ALL;
# 关闭自动归档
ALTER DATABASE NOARCHIVELOG;
# 清空归档日志
ALTER SYSTEM SWITCH LOGFILE;

# backup
DELETE BACKUP; 

alter user system identified by password;
ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME UNLIMITED;
ALTER SYSTEM SET db_create_file_dest = "/home/oracle/app/oracle/oradata";
alter tablespace system add datafile '/home/oracle/app/oracle/oradata/helowin/system2.dbf' size 10G autoextend off;

select tablespace_name,file_name,online_status from dba_data_files where tablespace_name='EXAMPLE';

alter system set processes = 2000 scope = spfile;