Re: What is null event ?

bchorng_at_yahoo.com said...
> I constantly see some sessions in "null event" in v$session_wait,
> but the sessions appear to be working hard. I can see that CPU time
> continues to increase for these processes. But they are not hung,
> as eventually, they will quiet down and change into SQL*Net message
> from client.
>
> I searched OTN on description of wait events, Oracle does not
> bother to explain what that is.
>
> How is it different from SQL*Net message from client ?
>
> Also, I don't recall seeing this event in 8i at all.
>
> I am running 9.2.0.3 on Solaris 8.
>
> Thanks.
>

You might want to head over to the AskTom site. He doesn't have much, but you can search for "null event" (include the quotes) and get a couple of hits, including this document (url will wrap):

http://asktom.oracle.com/pls/ask/f?p=4950:8:1090762::NO::F4950_P8 _DISPLAYID,F4950_P8_CRITERIA:6108562636780, Basically, unless you compare diffs between two snapshots, the "null event" is meaningless.

BTW, be sure to read Tom's "other common sense things I hear all the time". It's his followup to the 5 Feb 2003 question from CPU Hungry (Tom does have a sense of humor).

-- 
/Karsten
DBA > retired > DBA