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Re: ORA-600 Deadlock Issues

From: Radoulov, Dimitre <cichomitiko_at_gmail.com>
Date: Mon, 27 Jun 2005 10:19:26 +0200
Message-ID: <00af01c57af0$f059e4d0$1a03310a@IBME1D11967173>


> look up chapter 7 of tom kytes' book - Indexes on Foreign Keys. (page 142
> in my book).
>
> "The number one cause of deadlocks in the Oracle database, in my
> experience, is unindexed foreign keys" - says the Guru himself.

The next time you have a deadlock, check first the deadlock graph, for unindexed foregn keys it will be SX-SSX:

Deadlock graph:

                       ---------Blocker(s)--------  ---------Waiter(s)---------
Resource Name          process session holds waits  process session holds 
waits
TM-000010e0-00000000        14      40    SX   SSX       13      19    SX 
SSX
TM-000010e0-00000000        13      19    SX   SSX       14      40    SX 
SSX
session 40: DID 0001-000E-00000002      session 19: DID 0001-000D-00000002
session 19: DID 0001-000D-00000002      session 40: DID 0001-000E-00000002




Cheers
Dimitre Radoulov

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Received on Mon Jun 27 2005 - 04:24:54 CDT

Original text of this message

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