Re: V$session_wait.seconds_in_wait

From: Mark D Powell <Mark.Powell_at_eds.com>
Date: Tue, 22 Jul 2008 06:42:02 -0700 (PDT)
Message-ID: <7ffd555f-551d-45c1-bc08-3da08c7e05ea@8g2000hse.googlegroups.com>


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
> > meÖ 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 itís latter, then why
> > the block# is not changing? Why itís reading the same block again &
> > again? Iím trying to figure if I have a i/o issue or notÖ
>
> 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

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