To err is human, to recover is DBA

emctl status dbconsole        (without semicolon)
emctl start dbconsole
emctl stop dbconsole

Change DBID in database

shu immediate

startup mount

nid target=/ logfile=change_dbid.log

change_dbid.log

startup mount

alter database open resetlogs;

Change dbname

shu immediate

startup mount

create pfile='D:\app\dbs\initorcl2.ora' from spfile;

nid target=sys/sys123@orcl dbname=orcl2 setname=yes logfile=db_change_name.log

open pfile and change orcl to orcl2

startup pfile='pfile='D:\app\dbs\initorcl2.ora';

Active Query

SELECT 

    s.sid, 

    s.serial#, 

    s.username, 

    s.osuser, 

    s.machine, 

    s.status, 

    s.sql_id,

    ROUND(s.last_call_et / 60, 2) AS elapsed_minutes

FROM 

    v$session s

WHERE 

    s.status = 'ACTIVE' 

    AND s.type != 'BACKGROUND'

    AND s.last_call_et > 60 -- Filters for queries running over 60 seconds

ORDER BY 

    s.last_call_et DESC;

Long Running Query

SELECT 

    sid, 

    serial#, 

    opname, 

    target, 

    sofar, 

    totalwork, 

    ROUND(sofar/totalwork*100, 2) AS "%_COMPLETE",

    start_time,

    ROUND(elapsed_seconds / 60, 2) AS elapsed_mins,

    ROUND(time_remaining / 60, 2) AS remaining_mins

FROM 

    v$session_longops

WHERE 

    time_remaining > 0 

    AND totalwork > 0;