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From Rick Hillegas <Richard.Hille...@Sun.COM>
Subject Re: Concurrency in connections and Threads
Date Wed, 09 Nov 2005 19:35:15 GMT
Hi Arieh,

I haven't run any experiments but I would expect that you would have to 
be careful about how you commit this work. If one thread commits the 
connection while another thread is in the middle of a statement, someone 
is likely to be disappointed.

You will likely have deadlock issues if you try to scale your 
application by running two teams of threads, each working on its own 
connection.

Regards,
-Rick



Arieh Markel wrote:

> I am using Derby in 'embedded' mode.
>
> A pool of worker threads takes jobs from a queue and following
> processing populates different tables.
>
> So far, in my implementation, all threads shared the same connection.
>
> I am wondering whether there are any resulting concurrency issues
> that I may not be aware of.
>
> My assumptions are as follows:
>
> - the threads are well behaved among themselves relative to (java) 
> concurrency
>
> - no two threads update the same database table at any given moment
>
> - table lock granularity is what is in place in Derby
>
> Based on that, the same connection (albeit processing different tables)
> may be used by different threads without creating unnecessary contention.
>
> Are those assumptions true ?
>
> Thanks,
>
> Arieh
>
> PS: please, reply directly, as I am not in the aliases ...
>


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