Blocking locks for how long ?

Question

Oracle 10.2.0.3 on solaris :
I have the following select statement that get me the blocked sessions with the blocker info and blockee info :
select s1.username || '@' || s1.machine || ' ( SID=' || s1.sid || ' ) is blocking '
|| s2.username || '@' || s2.machine || ' ( SID=' || s2.sid || ' ) ' AS blocking_status
from v$lock l1, v$session s1, v$lock l2, v$session s2 where s1.sid=l1.sid and s2.sid=l2.sid
and l1.BLOCK=1 and l2.request > 0 and l1.id1 = l2.id1 and l2.id2 = l2.id2 ;
How do I modify this SELECT statement to give me one more thing -- the amount of time the blockee has waited so far for the blocker to release the lock ?
Thanks

Answer 1

Sorry,,,I made my above comment without testing one more scenario(which obviously didn't work)
The GV$ views works in a scenario where, the blockee and blocker are on the same instance. For example, if both are on DATABASE02, The query with GV$ views works from DATABASE03(or DATABASE01) as well !!!
BUT, if the same object is being locked- and the blocker is on the DATABASE02 instance whereas the blockee is on DATABASE03 instance, my query does not fetch any rows.
My query is :
select s1.username ||
'@' ||
s1.machine ||
' ( SID=' ||
s1.sid ||
' SERIAL#=' ||
s1.serial# ||
' ) is blocking '||
s2.username || '@' || s2.machine ||
' ( SID=' ||
s2.sid ||
' SERIAL#=' ||
s2.serial# ||
') for the last '||
sw.seconds_in_wait ||
' seconds.'
AS blocking_status,
dbo.object_name ||
' is the object locked'
AS blocked_object
from gv$lock l1, gv$session s1, gv$lock l2, gv$session s2, gv$session_wait sw , dba_objects dbo, gv$locked_object lo
where s1.sid=l1.sid
and s2.sid=l2.sid
and l1.BLOCK=1 and l2.request > 0
and l1.id1 = l2.id1
and l2.id2 = l2.id2 and
sw.sid = l2.sid and
lo.session_id = s1.sid and
lo.object_id = dbo.object_id and
l1.sid = lo.session_id ;
Am I missing something here, or can the above query tweaked to return me the result ?
My test scenario is :
On instance DATABASE02(database is DATABASE00) - The blocker
create table tstlock (foo varchar2(1), bar varchar2(1));
insert into tstlock values (1,'a');
insert into tstlock values (2, 'b');
commit ;
select * from tstlock for update ;
On instance DATABASE03(database is DATABASE00) - The blockee
update tstlock set bar='a' where bar='a' ;
The expected result is :
USER1@COMPANY\MACHINE1 ( SID=163 SERIAL#=11766 ) is blocking USER2@COMPANY\MACHINE2 ( SID=164 SERIAL#=1570) for the last 61 seconds.
Thanks