Find the object that is causing a wait event

Dears,

I am trying to find the object that is causing a wait event.

I am using this query:

QUERY 1

select segment_name,segment_type,owner,tablespace_name from

dba_extents,v$session_wait

where file_id=p1

and p2 between block_id and block_id + blocks -1

and sid=67;

I run it several times but every time no rows were found …… I am afraid that QUERY 1 takes a lot of time to complete and the object´s information is not there anymore.

Is that right? …… I mean, Is it a problem that P1,P2 for the session 67 changes faster than the running time of