who,when,what,how locked an object ????

select /*+ rule */ aa.object_name,aa.owner,LL.LOCKED_MODE,
DECODE (LL.LOCKED_MODE,
0, 'none',
1, 'null',
2,'Row- Share',
3,'Row- exclusive',
4,'Share',
5,'Share /Row- exclusive',
6,'exclusive'
) Locked_Mode_Detail,
SES.PROGRAM ,LL.SESSION_ID,SES.SQL_ID ,TXT.LAST_ACTIVE_TIME, TXT.SQL_FULLTEXT
from dba_objects aa, v$locked_object ll, v$session ses, V$SQLAREA txt
where aa.object_id = LL.OBJECT_ID and LL.SESSION_ID=SES.SID and TXT.SQL_ID=SES.SQL_ID;


What queries are going on in my database on a particular object

select AR.PARSING_SCHEMA_NAME, AR.EXECUTIONS, AR.ELAPSED_TIME/1000000 "ELAPSED_SECOND", AR.ROWS_PROCESSED,AR.MODULE,AR.LAST_LOAD_TIME, AR.LAST_ACTIVE_TIME,AR.SQL_FULLTEXT

from v$sqlarea ar

where trunc(AR.LAST_ACTIVE_TIME,'MI') = trunc(sysdate,'MI') and upper(AR.SQL_FULLTEXT) like '%SAMPLE_TEXT%';

Total query list in my database
SELECT parsing_schema_name,LAST_LOAD_TIME,LAST_ACTIVE_TIME,EXECUTIONS,ELAPSED_TIME/1000000 ELAPSED_SEC,(ELAPSED_TIME/1000000)/EXECUTIONS*1000 AS "Avg.E.M.Sec",SQL_TEXT
FROM V$SQLAREA WHERE EXECUTIONS<>0
order by 6 desc;

In Oracle 9i

select first_load_time,sql_text from v$sqlarea
where trunc(to_date(first_Load_time,'yyyy-mm-dd/hh24:mi:ss'),'dd')=trunc(sysdate,'dd')
and parsing_schema_id=ur_given_userid;