"Root[Excl|Share]" are suspend reasons.
"Vbegexcl" means that a task is waiting before entering any critical section.
"Vsuspend" is an unnamed reason, only the reason id gives a hint with "x_cons ... show
sus"
"Vwait" means that a task is waiting for a sql lock
(sql locks are requested before tree locks are requested)
So only the "Root.." suspend states give a hint for a high collision rate on tables.
If you use syskey's or similiar sequences as a key you have an additional hotspot on
the rightmost leaf. So here you are right that when root locks are held longer the
longer you spend time in waiting for leaves and then you have more collsions.
kind regards,
Uwe
>-----Original Message-----
>From: Axel Busch [mailto:[EMAIL PROTECTED]
>Sent: Tuesday, September 07, 2004 5:02 PM
>To: Hahn, Uwe
>Cc: [EMAIL PROTECTED]
>Subject: Re: Task State "RootShare"
>
>
>Hello Uwe,
>
>thanks a lot. So it is similar Vsuspend? For me as an application
>developer, is it save to assume that many occurences of
> Vbegexcl
> Vsuspend
> Vwait
> RootShare
> RootExcl
>indicate that too many tasks are accessing the same leaf
>simultaneously and/or spend too much time in one?
>
>regards,
>Axel
>
>Hahn, Uwe wrote:
>
>> Hi Axel,
>>
>> RootShare means that a task wants to lock a btree in share
>mode but has to wait
>> because another task holds a RootExcl lock on the same btree root.
>> The RootShare lock is needed for reading in leaves or for
>updating one leaf.
>> The RootExcl lock is set if a task needs to add or remove
>another leaf to the btree.
>>
>> regards,
>> Uwe
>>
>>
>>>-----Original Message-----
>>>From: Axel Busch [mailto:[EMAIL PROTECTED]
>>>Sent: Tuesday, September 07, 2004 11:34 AM
>>>To: [EMAIL PROTECTED]
>>>Subject: Task State "RootShare"
>>>
>>>
>>>Hi,
>>>
>>>I was dumping the task state of our database instance during a
>>>sudden increase in database connections (from 2 to 150 in 10
>>>seconds) with x_cons, and ran across the state "RootShare".
>>>This state is not documented, but since most of the tasks are in
>>>this state, I would be _very_ interested in what it says.
>>>
>>>Can somebody please sketch quickly what it says? Actually I need
>>>this rather urgently, since we have some serious freezing problem.
>>>
>>>kind regards and thanks in advance,
>>>
>>>Axel
>>>
>>>
>>>
>>
>>
>
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