From:Steve Adams
Date:20-Nov-2000 09:39
Subject:   Deadlock issue

This is a simple row-level lock deadlock. Both the missing foreign key issue and the ITL entry shortage issue can be excluded on the grounds that both sessions are wanting exclusive locks.

I have been trying to find the cause for this deadlock and posted this to Oracle-L and Lazydba lists and comp.database.oracle.server. As usual the one and only reply suggestes me to escalete to IXORA. Can you help me in this?

I think you're right. It's not an fk-related problem, because your sessions try to get not share locks but exclusive locks. I'm not sure, but maybe it's related to low value of the INITRANS? Do you have many concurrent sessions which try to update the table? You can find some info about deadlocks at http://www.ixora.com.au/.

Can anyone tell me the cause for these deadlocks? Initially I had thought this is related to index-foreign key issues. Now those foreign keys are indexed and all objects are valid. Any thoughts? 
  Deadlock graph:
                         ---------Blocker(s)-------- ---------Waiter(s)---------
  Resource Name          process session holds waits process session holds waits
  TX-00090014-00003434        12      13     X            38      39           X
  TX-00050032-000032fa        38      39     X            12      13           X