I have HP prolient ML350 server having 2 cpu (3 ghz xenon) & 3 gb ram running windows 2000 server. I have oracle 126.96.36.199.0. I am getting a problem when ever i connect as (system) user from client machine in v$session_wait view it shows that user as NULL EVENT & having following output .
There have been instances of 9i version of oracle masking the actual wait events with the "null event". You can maybe enable event 10046 for the session that's experiecing the "null event" and see if the event can trace the actual wait events that might be occuring. To enable event 10046 for a different session, you can use the dbms_system.set_ev procedure:
Actually "NULL EVENT" can be found in v$event_name in 9i.
1 select name from v$event_name
2* where name = 'null event'
My guess is:
Since there are 800 events in 10g and 400 in 9i, the kernel developers of ORACLE suggested to add this in 9i, so that their code can be easily modified later in 10g to accomodate more specific events.
Yes, "null event" is a valid idle wait event that can potentially occur when a piece of code (explicit or implicit) calls the wait interface without an event id. However, for 9i version of oracle, there is a known bug that has been fixed in 188.8.131.52 where oracle has replaced "null event" with "unspecified event" to indicate a wait state
where no named event has been supplied.
The individual who has posted below has the problem with the "null event" wait event in 184.108.40.206 and that's one of the versions of 9i being affected.