оЕПЕЯШКЙЮ: Triggers and Locks

["Shulzhenko Vasyl" <vasilis@softline.kiev.ua>]

>Tim Owens wrote:
>> 
>> I have a question about how an AFTER action on a trigger affects locks.
>> 
>> If process A updates a row in a table with an "AFTER" trigger, will
>> process A's lock be released before the "AFTER" action takes place,
>> or will process A's lock be held until the "AFTER" action is completed.
>> 
>> I am trying to solve a deadlock problem that seems to be related to
>> triggers/stored
>> procedures, and would very much appreciate any response.
>
>The lock has to be held until the end of the transaction which 
>certainly includes the AFTER action of the UPDATE trigger.  If you are 
>executing a singleton UPDATE statement, without a BEGIN WORK the scope 
>of the transaction is actually the entire UPDATE statement and 
>therefore the locks will not be released until the entire UPDATE 
>completes on all affected rows.  If you have started an explicit 
>transaction, ie BEGIN WORK; ...... COMMIT WORK; then that is the scope 
>of the transaction.
>
>Art S. Kagel