SQL backing an LDAP directory

There are two possibly reasons why a lazy admin would want to layer an LDAP directory on top of an SQL database.

1. One is for using SQL as a storage backend for an LDAP directory. This is hardly rational, since BDB will give you much better performance. (This goes for OpenLDAP. I’m not very knowledgeable on other implementations. — Rowan Rodrik van der Molen 2006/09/07 04:19)
2. The other is the usage of LDAP as an access protocol to an SQL database. (E.g.: if you store contacts in your database and you want to use the contacts’ details from an LDAP supporting application, such as most email clients, you could use LDAP as an access protocol to your SQL DB.)

1. OpenLDAP‘s slapd includes the back_sql SQL back-end.
2. ruby-ldapserver is an easy to use, lightweight skeleton for writing your own LDAP server application in Ruby.