Re: [cx-oracle-users] Thread commits - do other threads get committed? Use Pooling?

[Anthony T. <ant...@gm...>]

On Tue, Nov 9, 2010 at 6:20 PM, Chapman, Scott <Sco...@pi...> wrote:
>
>
> -----Original Message-----
> From: Amaury Forgeot d'Arc [mailto:ama...@gm...]
> Sent: Tuesday, November 09, 2010 4:01 PM
> To: cx-...@li...
> Subject: Re: [cx-oracle-users] Thread commits - do other threads get
> committed? Use Pooling?
>
>> > 2010/11/10 Chapman, Scott <Sco...@pi...>:
>> > If I use pooling, do I need to make the Connections threaded=True?
> (I'm
>> > thinking no, because each thread will grab a connection from the
> pool,
>> > begin and commit a transaction and release it's connection back to
> the
>> > pool).
>
>> Yes you need "threaded=True"; this is mostly a signal for the Oracle
>> OCI library to synchronize access to shared resources like memory and
>> other global structures.
>
> You're saying the threaded flag is doing more than the cx_Oracle docs
> say it does, "indicates whether or not Oracle should use the mode
> OCI_THREADED to wrap accesses to connections with a mutex."  This is
> supposed to be used when different threads are using a Connection object
> simultaneously. If you're got a Connection Pool then each thread
> acquires the connection for the duration and so I'm thinking threaded
> does not need to be set.  Are you quite sure of your interpretation of
> the flag?

Look here at the Oracle documentation for OCI_THREADED

http://www.di.unipi.it/~ghelli/didattica/bdldoc/B19306_01/appdev.102/b14250/oci09adv.htm

Basically, thread safety is already maintained internally for each
environment handle by the Oracle libraries (in cx_Oracle an
environment handle is created for each connection) and its only if you
want to make use of the __same__ connection in multiple threads that
you need the threaded = True constructor argument. Hope that makes
sense!

Anthony