Re: V$session_wait.seconds_in_wait

On Jul 21, 8:28 pm, Charles Hooper <hooperc2..._at_yahoo.com> wrote:
> On Jul 21, 6:00 pm, mak..._at_gmail.com wrote:
>
>
>
>
>
> >    SELECT      sid ,event,state,
> >                seconds_in_wait siw,wait_time,p1text p1txt,p1,p2text
> > p2txt,p2,p3text p3txt,p3
> >    FROM        v$session_wait WHERE       sid = &sid
>
> >    SID Wait Event           Wait State       SIW    wait_time
> > P1TXT                P1 P2TXT         P2       P3TXT               P3
> > ------ -------------------- ------------- -------- --------
> > ----------   ------------ --------      -------- --------
> > --------
> >   4000 direct path read temp WAITED KNOWN      909        1     file
> > numbe         4523 first db      2651740  block cn             1
> >   4000 direct path read temp WAITED KNOWN      913        1     file
> > numbe         4523 first db      2651740  block cn             1
> >   4000 direct path read temp WAITED KNOWN      916        1     file
> > numbe         4523 first db      2651740  block cn             1
>
> > Can someone interpret this 3 successive reading for above query for
> > me… Seconds_in_wait & wait_time are confusing me..
>
> > Is it one DPRT (direct path read temp) taking 900+ seconds or is it
> > 900+ DPRT that are taking 1/100 sec each?  If it’s latter, then why
> > the block# is not changing? Why it’s reading the same block again &
> > again? I’m trying to figure if I have a i/o issue or not…
>
> Based on the notes that I have, SECONDS_IN_WAIT is meaningless when
> STATE is anything other than WAITING.  The session waited roughly 1
> second reading 1 block from file# 4523, possibly for the purpose of
> reading the results of a sort to disk.
>
> Charles Hooper
> IT Manager/Oracle DBA
> K&M Machine-Fabricating, Inc.- Hide quoted text -
>
> - Show quoted text -

A very complete answer to this same question was posted on the OTN database forum today.

The Oracle version# Reference Manual includes coverage of this v$ view and the meaning of its columns. The time units in the view vary by Oracle release and are the values are only approximate wait times.

HTH -- Mark D Powell -- Received on Tue Jul 22 2008 - 08:42:02 CDT