Improve performance of hibernate and other things that use DB connections without actually calling the DB via lazy proxy

One of the Spring masters suggested this to me today. In order to
reduce database load, you put a lazy proxy in between the datasource
and the users (consumers) of it. This means the actual connection is only opened
when it is used and if there are things (like hibernate or some
transactional wrappers) which always open a connection then it does
not waste the connection if the hibernate cache has the value or the
connection is not actually used. This has been around since Spring 1.1 is
highly tested and reliable.

The change would be something like this in
/db-impl/pack/src/webapp/WEB-INF/components.xml (replace the current
bean with the id of javax.sql.DataSource with the two beans below):
<!-- Shared DataSource for all pooled database connections -->
<bean id="javax.sql.TargetDataSource" parent="javax.sql.BaseDataSource" />

<!-- Proxy which will keep only get the connection if one is
actually needed,
this is especially helpful when using hibernate or wrapping
transactions around requests
because it keeps the connection from being opened and held if
it is not needed -->
<bean id="javax.sql.DataSource"
class="org.springframework.jdbc.datasource.LazyConnectionDataSourceProxy">
<property name="targetDataSource"><ref
local="javax.sql.TargetDataSource" /></property>
</bean>