equijoin

equijoin: объединение по эквивалентности (отношений в реляционных базах данных) объединение по эквивалентности

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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
Joinalgorithmen — sind mögliche Strategien (Algorithmen) zur Implementierung von Joins. Die optimale Strategie hängt von Größe und Struktur der am Join beteiligten Relationen, verwendeten oder verwendbaren Indizes, der Größe des Hauptspeichers als auch der Join… … Deutsch Wikipedia
Join (SQL) — An SQL join clause combines records from two or more tables in a database.[1] It creates a set that can be saved as a table or used as is. A JOIN is a means for combining fields from two tables by using values common to each. ANSI standard SQL… … Wikipedia
Pullback (category theory) — In category theory, a branch of mathematics, a pullback (also called a fibered product or Cartesian square) is the limit of a diagram consisting of two morphisms f : X → Z and g : Y → Z with a common codomain. The pullback is often written: P = X … Wikipedia
Álgebra relacional — El álgebra relacional es un conjunto de operaciones que describen paso a paso como computar una respuesta sobre las relaciones, tal y como éstas son definidas en el modelo relacional. Denominada de tipo procedimental, a diferencia del Cálculo… … Wikipedia Español

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