In chapter 3 of the book on page 35, Rod writes:

"With some persistence technologies, we may need to explicitly disconnect objects from the persistence store."

In what situations would you want to disconnect objects from a persistence store? Can someone provide some scenarios/examples of what Rod meant?

I had a discussion with a colleague of mine and he explained when persistent objects are retrieved from a database, that the typical strategy is to copy properties to a value holder and release the persistent object back to the pool. Disconnecting the object from the persistent object pool is an alternative approach that current ORM vendors have provided to eliminate the requirement of value holders.

Forgive my ignorance on this issue. My background has been primarily with pure JDBC persistence; I have limited experience with OJB, Apache's ORM offering.