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From "Johnny Kewl" <j...@kewlstuff.co.za>
Subject Re: embedded db and connection pooling
Date Wed, 04 Jun 2008 12:06:48 GMT

----- Original Message ----- 
From: "Robert J. Carr" <rjcarr@gmail.com>
To: "Derby Discussion" <derby-user@db.apache.org>
Sent: Tuesday, June 03, 2008 9:04 PM
Subject: Re: embedded db and connection pooling


> Hey Kristian-
>
> Thanks for the response, here's some comments:
>
>> Do you delete the files on disk and connect to the same database (again), 
>> or
>> are you creating a brand new database (with a different name / 
>> directory)?
>
> I will admit that what I was doing was illogical and I never should
> have expected it to work.  I was basically deleting the database files
> between deployments of my web application.  Since I switched to jndi
> data sources, where tomcat now owns the connection not my web app,
> this will no longer work.
>
http://www.pinkdragon.net/doc_lib/contents/en/tomcat_6_0/jndi-resources-howto.html

Robert, read the second paragraph... "per webapp basis"
This is what I think... if its set up for a global resource TC thinks you 
using the dB across all webapps.
So the pool is set  up and remains setup even when a new webapp is added.
In this case, deleting the dB and rebuilding is bad news because TC is still 
using it.
But on a "per webapp" basis, you undeploy, do what you will, and on a 
redeploy, the connections a remade for that webapp only.

It seems to just depent on whether you have the JNDI setup in sever.xml 
(global) or web-inf/context (webapp only)

Have fun...

ps if you want a independent dB pool... can steal the lib and demo code here
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