Even though LDAP schema is very extensible, it never took off as an extensible data store. You can find many books showing how to model an object into 3nf for example, but few that demonstrate this with LDAP.

I worked at a company that used LDAP as a backend data store for users, publishers, and subscriptions. Many times we talked about moving the data to a relational database mainly because third normal form is very established and LDAP design patters are lacking.

For example, several times I would get a request from a developer to add different elements to the schema. Then I would ask back "How should I index this data?" then would say "Turn on all the indexes", this is usually a bad idea, and it showed that they did not understand the implications of schema and indexing at a very high level.

LDAP as a custom data store turns out to be a very interesting way to store data. We had a very fast, fairly large directory. Being able to have a hierarchical layout rather then join tables was very effective for our application.

IMHO. the problem is that most documents on the subject use LDAP only as a user directory, and do not do much to suggest other ways to use it.

On Sun, Dec 27, 2009 at 6:08 PM, Murray S. Kucherawy msk@cloudmark.com wrote:

Is the 1997 book “LDAP: Programming Directory-Enabled Applications” by Smith & Howes reasonably current to the latest OpenLDAP releases, or has enough changed in the intervening 12 years that it’s not worth getting?