Relational algebra — Not to be confused with Relation algebra. Relational algebra, an offshoot of first order logic (and of algebra of sets), deals with a set of finitary relations (see also relation (database)) that is closed under certain operators. These operators … Wikipedia
Bénévolat — Le bénévolat est une activité non rétribuée et librement choisie qui s’exerce en général au sein d’une institution sans but lucratif (ISBL) : association, ONG, syndicat ou structure publique. Celui ou celle qui s’adonne au bénévolat est… … Wikipédia en Français
SQL — This article is about the database language. For the airport with IATA code SQL, see San Carlos Airport. SQL Paradigm(s) Multi paradigm Appeared in 1974 Designed by Donald D. Chamberlin Raymond F. Boyce Developer … Wikipedia
IBM Business System 12 — Business System 12, or simply BS12, was one of the first fully relational database management systems, designed and implemented by IBM s Bureau Service subsidiary at the company s international development centre in Uithoorn, The Netherlands.… … Wikipedia
Ball lightning — is an atmospheric electrical phenomenon, the physical nature of which is still controversial. The term refers to reports of luminous, usually spherical objects which vary from pea sized to several meters in diameter. It is sometimes associated… … Wikipedia
Query language — Query languages are computer languages used to make queries into databases and information systems. Broadly, query languages can be classified according to whether they are database query languages or information retrieval query languages. The… … Wikipedia
Projection (relational algebra) — IntroductionIn relational algebra, a projection is a unary operation written as pi {a 1, ...,a n}( R ) where a 1,...,a n is a set of attribute names. The result of such projection is defined as the set obtained when the components of the tuple R… … Wikipedia
Fondation Université de Strasbourg — Informations Fondation 2008 Type Fondation partenariale … Wikipédia en Français
Lightweight Directory Access Protocol — The Lightweight Directory Access Protocol (LDAP; /ˈɛld … Wikipedia
CODASYL — (often spelled Codasyl ) is an acronym for Conference on Data Systems Languages . This was a consortium formed in 1959 to guide the development of a standard programming language that could be used on many computers. This effort led to the… … Wikipedia