Directory

Almanac with the Bottin

The first directories are the heirs to the Almanach appeared in Europe starting from the Moyen-Âge. The royal Almanac published at the origin for Louis XIV, thus makes an inventory of the senior officials of the State and the professors of the universities. It becomes gradually a “true directory of the French administration” until its disappearance in 1913.

In 1763 appears the Almanach of Gotha , which gathers information on the royal families of Europe, and which will be subtitle in 1944 genealogical Annuaire, diplomatic and statistical . A few years later, Sebastien Bottin publishes the Almanach commercial and industry , and will give its name to this form of publication, like with other directories, like the greedy Bottin or the Bottin society man .

The most known directory is that of the subscribers of the Téléphone, which is generally distributed between the Yellow pages (for the professionals) and the White pages (for the private individuals). But various professional, administrative or university structures can publish directories made up of the coordinates of former students, customers, members or participants in a program.

In data processing

In the world of data processing, a directory is a system of data storage, derived from the hierarchical databases, making it possible in particular to preserve the perennial data, i.e. the data being only updated little (historically, on an annual base, from where the name), like the coordinates of the people, the partners, the customers and the suppliers of a company. This is why, thanks to optimizations, a directory is much faster in consultation than in update.

Characteristics

It is a system which organizes physical or numerical information; any electronic directory includes in particular:

a index which facilitates the communication between entities
a hierarchical organization optimized for an rapid access with many information in small volumes
of the entities and objects in the shape of people, communities, resources or equipment
of the access to the databases updated by the users of the computer applications.

Principal standards

X.500 indicates the whole of the data-processing standards on the services of directory defined by UIT-T. But only the X509 part concerning the Authentification is currently used; for the remainder, the majority of the current services of directory use a standard much less heavy: LDAP.
LDAP (for Lightweight Directory Access Protocol ) is a protocol allowing the interrogation and the modification of the services of directory. This protocol rests on TCP/IP. A directory LDAP generally respects model X.500: it is a tree structure of which each node makes up of attributes associated with their values.
UDDI : this standard created in October 2000 is used for the E-business.

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