In general LDAP servers and RDBMS are DESIGNED to provide different types of services. LDAP is an open standard access mechanism, so an RDBMS can talk LDAP. HOWEVER the servers, which are built on LDAP, are optimized for read access so likely to be much faster than RDBMS in PROVIDING read access. So in a nutshell, LDAP is more useful when the information is often searched but rarely modified. (Another difference is that RDBMS systems store information in rows of tables whereas LDAP uses object oriented hierarchies of entries.) . Key LDAP Terms:

• DIT: Directory Information Tree. Hierarchical structure of entries, those make up a directory.
• DN: Distinguished Name. This uniquely identifies an entry in the directory. A DN is made up of relative DNs of the entry and each of entry's parent entries up to the root of the tree. DN is read from right to left and commas separate these names. For example 'cn=Peter Smith, o=ACME, c=AUS'.
• objectClass: An objectClass is a formal definition of a specific kind of objects that can be stored in the directory. An ObjectClass is a distinct, named set of attributes that represent something concrete such as a user, a computer, or an application.
• LDAP URL: This is a string that specifies the location of an LDAP resource. An LDAP URL consists of a server host and a port, search scope, baseDN, filter, attributes and extensions.
• LDAP schema: defines rules that specify the types of objects that a directory may contain and the required optional attributes that entries of different types should have.
• Filters: In LDAP the basic way to retrieve DATA is done with filters. There is a wide variety of operators that can be used as FOLLOWS: & (and), | (or), ! (not), ~= (approx equal), >= (greater than or equal), <= (less than or equal), * (any) etc.

In general LDAP servers and RDBMS are designed to provide different types of services. LDAP is an open standard access mechanism, so an RDBMS can talk LDAP. However the servers, which are built on LDAP, are optimized for read access so likely to be much faster than RDBMS in providing read access. So in a nutshell, LDAP is more useful when the information is often searched but rarely modified. (Another difference is that RDBMS systems store information in rows of tables whereas LDAP uses object oriented hierarchies of entries.) . Key LDAP Terms: