Quote from J2EE Tutorial
What Is a Session Bean?
"As its name suggests, a session bean is similar to an interactive session. A session bean is not shared--it may have just one client, in the same way that an interactive session may have just one user..."
What Is an Entity Bean?
"What Makes Entity Beans Different from Session Beans?
Entity beans differ from session beans in several ways. Entity beans are persistent, allow shared access, have primary keys, and may participate in relationships with other entity beans.
Entity beans may be shared by multiple clients..."
I think what you concern or we concern is how the entity bean presist data, if it is CMP, the persistence job is handled by the container, and what I experience is whenever I call the set methods, it presists, and when I have lock the record by other means, the operation suspends.
And with BMP, it persists whenever the ejbStore method is invoked, so I think it is not so critical that the container will handle such jobs for us.