In the preceding sections, you have seen how to interact with a relational database. In this section, we briefly look at hierarchical databases that use LDAP, the Lightweight Directory Access Protocol. This section is adapted from Core JavaServer Faces by Geary and Horstmann [Sun Microsystems Press 2004].
LDAP is preferred over relational databases when the application data naturally follows a tree structure and when read operations greatly outnumber write operations. LDAP is most commonly used for the storage of directories that contain data such as user names, passwords, and permissions.
For an in-depth discussion of ...