If you have a true deadlock, then you won't need to kill processes. SQL has a deadlock detector that will notice a deadlock condition, pick one of the participants and kill it automatically.
Do you have true deadlocks (if so, the users will be getting occasional errors about processes been picked as the deadlock victim and rolled back) or do you just have long-term blocking?
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: Discussions on DB performance with occasional diversions into recoverability
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