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Re: The 5-minute interval in sys.smon_scn_time table

From: EscVector <Junk_at_webthere.com>
Date: 1 Dec 2006 11:54:12 -0800
Message-ID: <1165002851.991315.158770@n67g2000cwd.googlegroups.com>

On Dec 1, 2:37 pm, "EscVector" <J..._at_webthere.com> wrote:
> On Dec 1, 11:52 am, DA Morgan <damor..._at_psoug.org> wrote:
>
>
>
> > Challenge wrote:
> > > Oracle version is 9.2.0.7 on AIX 5.2
>
> > > Any idea why the interval is 10 mins instead of 5 mins? Thanks.
>
> > > DA Morgan wrote:
> > >> Challenge wrote:
> > >>> Hi,
>
> > >>> According to the document, the smon_scn_time table will be updated
> > >>> automatically by SMON every 5 minutes. Why the interval of the
> > >>> smon_scn_time table is 10 minutes in my database?
>
> > >>> THREAD TIME_MP TIME_DP SCN_WRP SCN_BAS
> > >>> ---------------- -----------------
> > >>> ------------------------------------- -------------------
> > >>> ----------------
> > >>> ......
> > >>> 1 1164280062 2006-11-23 06:07:43 0
> > >>> 404008
> > >>> 1 1164280662 2006-11-23 06:17:43 0
> > >>> 404209
> > >>> 1 1164281262 2006-11-23 06:27:43 0
> > >>> 404410
> > >>> 1 1164281862 2006-11-23 06:37:43 0
> > >>> 404611
> > >>> 1 1164282462 2006-11-23 06:47:43 0
> > >>> 404812
> > >>> 1 1164283062 2006-11-23 06:57:43 0
> > >>> 405013
> > >>> 1 1164283662 2006-11-23 07:07:43 0
> > >>> 405214
> > >>> 1 1164284262 2006-11-23 07:17:43 0
> > >>> 405415
> > >>> 1 1164284862 2006-11-23 07:27:43 0
> > >>> 405616
> > >>> ......
>
> > >>> Thanks.
>
> > >> And your version is?
> > >> --
> > >> Daniel A. Morgan
> > >> University of Washington
> > >> damor..._at_x.washington.edu
> > >> (replace x with u to respond)
> > >> Puget Sound Oracle Users Group
> > >>www.psoug.orgHopefullysomeone knows but I will check and see if I can find
> > out. My first thought: Documentation error. But it may be something
> > else.
> > --
> > Daniel A. Morgan
> > University of Washington
> > damor..._at_x.washington.edu
> > (replace x with u to respond)
> > Puget Sound Oracle Users Groupwww.psoug.orgQuick sample 10.2.0.2 on AIX 5.3
> Total default config for used for testing.
> Looks like 5 min on this system...
> 12/01/2006 13:58:21
> 12/01/2006 14:03:52
> 12/01/2006 14:05:25
> 12/01/2006 14:10:37
> 12/01/2006 14:15:51
> 12/01/2006 14:17:27
> 12/01/2006 14:22:28
> 12/01/2006 14:27:53
> 12/01/2006 14:33:05

Found this on metalink:

Subject: Parameters FLASHBACK_SCN And FLASHBACK_TIME: Point In Time Export

  	Doc ID: 	Note:204334.1 	Type: 	BULLETIN
  	Last Revision Date: 	25-JUN-2004

b. The time specified in FLASHBACK_TIME is mapped to a SCN value. Currently,

      the SCN-time mapping is recorded every 5 minutes after database startup.

      Thus it might appear as if the specified time is being rounded down by

      up to 5 minutes. Due to this time-to-SCN mapping, a flashback export for

      a time immediately after creation of a table may result in an ORA-1466
      error. An SCN-based flashback export therefore gives you a more precise

      way to retrieve a past snapshot of data.

No search indicates how the interval is set. Received on Fri Dec 01 2006 - 13:54:12 CST

Original text of this message

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