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From Shreyas Kaushik <Shreyas.Kaus...@Sun.COM>
Subject Re: Aborting SQL Statements
Date Wed, 23 Feb 2005 11:59:56 GMT
Hi all,
 
 Can the implementation of canel() for embedded mode be done by closing the
activation for that particular statement when the query times out?

thanks
Shreyas

Satheesh Bandaram wrote:

> Right... Cancel() is going to be the tricky one to implement.
>
> Satheesh
>
> Daniel John Debrunner wrote:
>
>>Satheesh Bandaram wrote:
>>
>>
>>  
>>
>>>But I think Derby's client JDBC driver, currently the IBM Universal
>>>driver, has some support. (I haven't tested it..) IBM recently announced
>>>contributing a Derby Client to Apache. If this client code is accepted
>>>and has the implementation for setQueryTimeOut() and cancel(), it might
>>>be easy to adapt that code to Embed driver as well.
>>>    
>>>
>>
>>Cancel() is a requirement for setQueryTimeout(), as I think once the
>>timeout has expired, setQueryTimeout() would just call cancel() or its
>>underlying logic. Thus if you want to implement these features, you need
>>to start with cancel.
>>
>>I don't think the cancel in a network client will help in any way in
>>implementing cancel() in embedded. The cancel in embedded needs to know
>>about how queries or statements are executed. A starting point for
>>investigation would be to see how the engine handles Thread.interrupt().
>>Currently if a thread is interrupted the session/connection is closed, a
>>similar mechanism would be needed for cancel. And it might make sense to
>>change it so that if the thread is interrupted only the active statement
>>is cancelled, I know the connection closing surprised some Cloudscape
>>customers.
>>
>>Dan.
>>
>>
>>
>>  
>>

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