Re: v$undostat question

From: Chuck <>
Date: Fri, 15 Feb 2008 18:12:36 GMT
Message-ID: <oCktj.33$N95.28@trnddc03>

Mark D Powell wrote:
> On Feb 13, 10:00 am, Chuck <> wrote:

>> Oracle
>> How is it possible for maxquerylen to go from 1 to 9000 in a single 10
>> minute interval? Is this a bug? Can't find anything about it on
>> metalink. TIA
>> SELECT begin_time,
>>     end_time,
>>     maxquerylen
>> FROM v$undostat
>> WHERE begin_time BETWEEN
>> to_date('10-FEB-08 19:19:19', 'dd-mon-yy hh24:mi:ss')
>> AND
>> to_date('10-FEB-08 19:29:19',    'dd-mon-yy hh24:mi:ss')
>> ORDER BY begin_time;
>> ------------------ ------------------ -----------
>> 10-FEB-08 19:19:19 10-FEB-08 19:29:19           1
>> 10-FEB-08 19:29:19 10-FEB-08 19:39:19        9387
>> 2 rows selected

> Interesting. I have no clue and do not have the time to attempt to
> follow up the one idea I have. Namely if the database was just
> restarted about 19:39 on Feb 10 if the reported query run time could
> include the prior run time for a transaction that now was being rolled
> back after the restart or after a transaction failover.
> By any chance was the database re-started around the time of the first
> entry?

Nope. Instance has been up for nearly a year.

> Is TAF is use on this system? (If so, was there a failover)

TAF? The instance is on a clustered node (Veritas active/passive) but has stated above has been up on the same node for nearly a year.

> I bet the answer is no to both but those were the only ideas I had.
> That would leave a bug of some kind.

That's what I'm guessing too. Well, this instance will finally go to 10gR2 in about a month so I'm not too worried about it.

Thanks all. Just wanted to be sure I wasn't overlooking something. Received on Fri Feb 15 2008 - 12:12:36 CST

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