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Re: [eclipselink-users] one connection for each request! 
Read query's executed outside of a transaction use EclipseLink's
readConnectionPool, so each query will use a read connection from the read
pool.  This should not be an issue with internal or external connection
pooling, and allows improved sharing of the connections and avoids
transactional overhead for non-transactional read operations.

Why is a single readAllQuery triggering thousands of queries?  That is
probably the bigger problem, consider using indirection/lazy, join fetching,
or batch reading.

You can trigger the UnitOfWork to hold and use a single connection for its
life-cycle using beginEarlyTransaction(), in JPA there is also an
EclipseLink persistence unit option for using an exclusive connection.



ymajoros wrote:
> 
> Hi there,
> 
> We migrated a big application from classic toplink to EJB 3, glassfish,
> EclipseLink. Some big module is still using classic toplink queries for
> a lot of things. As we didn't have the resource to change everything to
> pure ejb & jpa, we tried a couple of "tricks". They kind of work (in
> production), but I noticed that there is one connection for each db
> request.
> 
> It stills works fast enough, thanks to Glassfish connection pooling. But
> I guess this is horrible. I also don't expect any
> 
> Here is how I get a UnitOfWork:
> 
> JpaEntityManager jpaEntityManager =
> JpaHelper.getEntityManager(entityManager);
> UnitOfWork unitOfWork = jpaEntityManager.getUnitOfWork();
> 
> Here is some eclipselink query which is causing thousand of db queries
> _and_ acquiring about the same number of connections :
> 
> ...
> return ((Collection) unitOfWork.executeQuery(readAllQuery));
> 
> thx
> 
> 


-----
http://wiki.eclipse.org/User:James.sutherland.oracle.com James Sutherland 
http://www.eclipse.org/eclipselink/
 EclipseLink ,  http://www.oracle.com/technology/products/ias/toplink/
TopLink 
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http://wiki.oracle.com/page/TopLink TopLink 
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http://www.nabble.com/EclipseLink-f26430.html EclipseLink 
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