Query to track the holder and waiter info

Question

Hi All,
I have framed the following query to get the blocker and holder info.
I intend to use this query in a auto-generated mail which executes every 15 mins
I have put an outer join on the holder because the holder DML might have completed its execution (v$sqlarea might not have info about this holder DML) at the time the auto mail configuration fires this query
I am not a dba and was apprehensive if there is some mistake in the logic of my query.
I was also expecting to join v$sql_bind_capture using sql_hash_value and sql_address just the way in which I have joined v$sqlarea
Looking forward to your kind help in vetting the below query
Select distinct waiting_session,
dba_waiters.holding_session,
decode(to_char(session_waiting_info.STATE),'0','waiter is currently waiting','-2','duration of last wait by waiter is unknown','-1','waiter waited for a short time',' waiter waited long time') "waiters waiting state",
decode(session_waiting_info.WAIT_TIME,0,'waiter waiting') "waiters last wait time",
decode(to_char(session_holding_info.STATE),'0','holder is currently waiting','-2','duration of last wait by holder is unknown','-1','holder waited for a short time','holder waited long time') "holders waiting state",
decode(session_holding_info.WAIT_TIME,0,'waiter waiting') "holders last wait time",
sql_waiting_info.sql_text "query of the waiter",
sql_holding_info.sql_text "query of the holder",
session_waiting_info.STATUS "waiting STATUS",
session_holding_info.STATUS "holding STATUS",
session_waiting_info.process "waiting process",
session_waiting_info.PROGRAM "waiting PROGRAM",
session_holding_info.process "holding process",
session_holding_info.PROGRAM "holding PROGRAM",
session_waiting_info.ROW_WAIT_OBJ# "waiting object",
session_waiting_info.ROW_WAIT_ROW# "waiting row",
session_holding_info.ROW_WAIT_OBJ# "holding object",
session_holding_info.ROW_WAIT_ROW# "holding row",
session_waiting_info.BLOCKING_SESSION_STATUS "waiting session status",
session_holding_info.BLOCKING_SESSION_STATUS "holding session status",
session_waiting_info.username "holding os username",
session_holding_info.username "waiting os username",
session_waiting_info.MACHINE "waiting MACHINE",
session_waiting_info.TERMINAL "waiting TERMINAL",
session_holding_info.MACHINE "holding MACHINE",
session_holding_info.TERMINAL "holding TERMINAL",
session_waiting_info.TYPE "waiting TYPE",
session_holding_info.TYPE "holding TYPE"
from dba_waiters,
v$session session_holding_info,
v$session session_waiting_info,
v$sqlarea sql_waiting_info,
v$sqlarea sql_holding_info
Where dba_waiters.waiting_Session = session_waiting_info.sid
and dba_waiters.holding_Session = session_holding_info.sid
And session_waiting_info.sql_hash_value = sql_waiting_info.hash_value
And session_waiting_info.sql_address = sql_waiting_info.address
and session_holding_info.sql_hash_value = sql_holding_info.hash_value(+)
And session_holding_info.sql_address = sql_holding_info.address(+)
and dba_waiters.mode_held 'None'
Regards,
Vishal

Answer 1

Hi Jonathan,
I have tried to incorporate your suggestions in the below query. Please let me know about the problems that the below query suffers from
select session_waiting_info.BLOCKING_SESSION,
     waiter.sid waiting_session,
     waiter.SECONDS_IN_WAIT,
     decode(session_holding_info.STATE,'WAITED SHORT TIME','Holder did not wait and is currently '||session_holding_info.STATUS,'WAITING','Holder is also waiting for the past '||session_holding_info.SECONDS_IN_WAIT ||' seconds','WAITED UNKNOWN TIME','Duration of last wait of holder is unknown','WAITED KNOWN TIME','Duration of last wait by the holder is:'||session_holding_info.STATE || ' and is currently '||session_holding_info.STATUS) "State of holder",
     sql_waiter_info.SQL_TEXT,
     bind_values.NAME,
     bind_values.VALUE_STRING,
     session_waiting_info.STATUS "waiting STATUS",
session_waiting_info.username "holding os username",
session_holding_info.username "waiting os username",
session_waiting_info.STATUS "waiting STATUS",
session_waiting_info.process "waiting process",
session_holding_info.process "holding process",
session_waiting_info.PROGRAM "waiting PROGRAM",
session_holding_info.PROGRAM "holding PROGRAM",
session_waiting_info.ROW_WAIT_OBJ# "waiting object",
session_waiting_info.ROW_WAIT_ROW# "waiting row",
session_holding_info.ROW_WAIT_OBJ# "holding object",
session_holding_info.ROW_WAIT_ROW# "holding row",
     session_waiting_info.sql_id,
     session_waiting_info.SQL_CHILD_NUMBER
from V$SESSION_WAIT waiter,
     V$SESSION session_holding_info,
     V$SESSION session_waiting_info,
     V$SQLSTATS sql_waiter_info,
     V$SQL_BIND_CAPTURE bind_values
where waiter.sid = session_waiting_info.sid
and session_waiting_info.BLOCKING_SESSION = session_holding_info.sid
and session_waiting_info.sql_id = sql_waiter_info.sql_id
and session_waiting_info.sql_id = bind_values.sql_id(+)
and session_waiting_info.SQL_CHILD_NUMBER = bind_values.CHILD_NUMBER(+)
and waiter.WAIT_TIME = 0
Regrds,
Vishal