Re: session wait fun

From: Tanel Poder <tanel_at_tanelpoder.com>
Date: Thu, 9 Jan 2014 23:34:01 +0200
Message-ID: <CAMHX9JLKNCZfPOA-nvvsjYkH=Qq4TzzzerciP3z_Qn2q883naQ_at_mail.gmail.com>

How do you extract these values? Just a simple select query or some GUI tool?

The seconds_in_wait column *physically* stores the *wait start time* as seconds from epoch in the memory location. And when you query this column in SQL, the underlying x$ reports the *current SGA time* - *wait start time*in seconds. Up to 10g, the current SGA time is mainained by LGWR and in
11g+ by VKTM.

Any non-SQL & direct SGA access approaches should account for that...

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*Tanel Poder*
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On Thu, Jan 9, 2014 at 10:03 PM, John D Parker <orclwzrd_at_yahoo.com> wrote:



> no offence taken! I hadn't thought about the epoch. ok, so how does the

> epoch get in to the seconds in wait column for a row in v$session? oh and

> I've confirmed this on a exadata as well. truly bizarre!

>

> Thanks!

>

>


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Received on Thu Jan 09 2014 - 22:34:01 CET