Corporate Directories

WORK IN PROGRESS

What is a Directory?

There is an excellent write up of what Directories are all about on the LDAPzone website.

A directory is primarily a hierarchical database for managing people related data.

Directories are designed to be massively fast at retrieving small amounts of data from very large data sets. To achieve this, they are comparatively "dumb" which means that controlling the consistency of the data needs to happen externally.

Directories containing 10's of millions of entries can easily be run on modest mid-range servers.

There are a number of international standards covering the basic data and structure of directories which allows for loosely coupled systems. See the standards for X.500 and LDAP primarily.

What is a Directory used for?

PKI,Identity management,white pages,...

What Directories are not good for?

Large numbers of writes compared to the number of reads (actually, this is much less of a problem for newer systems and can typically be managed using master and shadow directories).

Complex data processing. Directory databases have only simple commands and not the power and flexibility of SQL so processing must be done externally which could be a problem with large amounts of data being transmitted over a network.

Directory Products

• Microsoft Active Directory
• Novell
• Critical Path
• Siemens
• Netscape
• Maxware
• IBM, Unisys, etc.

Synchronising Directories