How can I find a segment name from p1 and p2 value of v$session??

Question

Hi, all.
A session is waiting with "gc cr request".
The pvalue of the session are as followings.
p1text p1 p2text p2 p3text p3
file# 15 block# 412 id# 33619969
I issued the following sql statement to find the segment name.
select segment_name
from dba_extents
where file_id = 15
and 412 between block_id and (block_id + blocks -1)
However, No row returned.
Is there any mistake??
Thanks and Regards.

Answer 1

Hi,
You will find what the wait means in the Oracle Reference manual.
http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/toc.htm
To find out what object P1 refers to:
select * from v$datafile where file# = file#;
To find the hot block within that object above do:
select name, kind from ext_to_obj_view
where file# = file#
and lowB <= block#
and highB >= block#;
to create a report an example change your variable to what you need
select
sess.username,
sess.sid,
se.event,
se.total_waits,
se.total_timeouts,
se.time_waited/100 time_waited,
se.average_wait
from v$session_event se, v$session sess
where event like '%buffer busy% <===== change to your choosing
and sess.sid = se.sid
and sess.username is not null
and se.total_waits > 10000
order by username, sid
hope this helps.
al