ORA-00054: resource busy and acquire with NOWAIT

There’s More than One Solution I would Love to Share :

1-Before 11g, you can mark the tablespace read-only for the duration of the alter table 

Alter Tablespace Test read only

2-in 11g you can mark table read-only :

Alter table test Read only

And You can Check Read Only Tables By :

Select    table_name, read_only from    dba_tables

Where owner = ‘myowner’ and table_name = ‘mytab’;

Just To Make Sure After You Alter table to Read Only prevent Update by Create Trigger

create or replace trigger

   tabl_read_only

before

   insert or update or delete

on mytab

begin

raise_application_error (-999999, ‘Table Is Read Only Now’);

end; /

3- You Can Check if there’s Lock on your Database :

SQL> set linesize 130

SQL> set pages 100

SQL> col username       format a20

SQL> col sess_id        format a10

SQL> col object format a25

SQL> col mode_held      format a10

SQL> select     oracle_username || ‘ (‘ || s.osuser || ‘)’ username

,  s.sid || ‘,’ || s.serial# sess_id

,  owner || ‘.’ || object_name object

,  object_type

,  decode( l.block

,       0, ‘Not Blocking’

,       1, ‘Blocking’

,       2, ‘Global’) status

,  decode(v.locked_mode

,       0, ‘None’

,       1, ‘Null’

,       2, ‘Row-S (SS)’

,       3, ‘Row-X (SX)’

,       4, ‘Share’

,       5, ‘S/Row-X (SSX)’

,       6, ‘Exclusive’, TO_CHAR(lmode)) mode_held

from       v$locked_object v

,  dba_objects d

,  v$lock l

,  v$session s

where      v.object_id = d.object_id

and        v.object_id = l.id1

and        v.session_id = s.sid

order by oracle_username

,  session_id

/

  Use

SQL> alter system kill session ‘SID,Serial# ‘;

Enjoy 
OSama Mustafa