Wow, thanks a lot.
This is clear, short, efficient. I'm trying it right now !

By the way, thanks for your blog that I read in the past and also helped me choosing OpenJPA.

On Sep 28, 2009, at 15:32 , Rick Curtis wrote:

I'd suggest using DBCP for connection pooling when not running in a JEE environment. Checkout this blog post [1] that I wrote about this very issue
a few months back.

-Rick

[1]
http://webspherepersistence.blogspot.com/2009/01/jpa-connection-pooling.html

On Mon, Sep 28, 2009 at 3:53 AM, Jean-Baptiste BRIAUD -- Novlog <
j-b.bri...@novlog.com> wrote:

OK, so is there a way to have add pool behavior with only JDBC (without
J2EE) ?



On Sep 28, 2009, at 05:04 , C N Davies wrote:

The doc says:

"EntityManagerFactory instances are heavyweight objects. Each factory
might
maintain a metadata cache, object state
cache, EntityManager pool, connection pool, and more."

"2.6.3. openjpa.jdbc.DriverDataSource
Property name: openjpa.jdbc.DriverDataSource
Configuration API:
org.apache.openjpa.jdbc.conf.JDBCConfiguration.getDriverDataSource
Resource adaptor config-property: DriverDataSource
Default: pooling"

"In its default configuration, OpenJPA obtains JDBC connections on an
as-needed basis. OpenJPA EntityManagers do not retain
a connection to the database unless they are in a datastore transaction or
there are open Query results that are using a live
JDBC result set. At all other times, including during optimistic
transactions, EntityManagers request a connection for each
query, then immediately release the connection back to the pool."


-----Original Message-----
From: Christopher Giblin [mailto:c...@zurich.ibm.com]
Sent: Monday, 28 September 2009 1:11 AM
To: users@openjpa.apache.org
Subject: relationship EntityManager and JDBC Connection?


Hi,

Does an EntityManager instance correspond one-to-one to a JDBC connection? When the EM is closed, is the JDBC connection closed? That is, by opening
and closing EMs, is one also opening and closing JDBC connections?

I am using OpenJPA with Derby. There is no connection pooling:

<property name="openjpa.ConnectionDriverName" value=
"org.apache.derby.jdbc.ClientDriver"/>

Sorry if I overlooked in the excellent documentation.

Thanks,chris





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