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Message Posted: Fri, 01 Jan 2010 @ 18:11:22 GMT


     
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Subj:   Re: Row Hash Deadlock in Active D/W due to concurrent MSR
 
From:   Mohd Suhail

Hello Victor,

Thank you for your suggestions. Using my case(query#1 and query#2), can you please elaborate further on the lock escalation/changing the order in the MSR part(perhaps with a simple example)?.

How can lock escalation cause a deadlock?

Further, how does changing the order help?

I'll surely go ahead and put forth these suggestions to my team but I would need a bit of understanding of the concept behind it.

To make the situation more clear, I'll explain the locking logger data we captured when one of the transaction got aborted due to 2631 deadlock error.

1. The blocked level is Row Hash.

2. The blocking level is Row Hash

3. Blocked username and blocking username are different

4. Table name is

5. Blocked mode and blocking mode are both 'WR'(write)

6. The value in the column:Deadlock is 'Y' (which implies that a deadlock has occured)

7. The value of the column: MULTIPLEBLOCKER is 'N'

8. The valud of the column: STMTTYPE is 'Update'


Also, would anyone know why sometimes the locking logger is unable to capture the lock data even though the transaction aborts due to deadlock?

Thank you for the thread links. They were very informative.


Regards,

Suhail



     
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