Se, theory> A family of algebra with a well-foundedSemanticS uSed for modelling the data Stored in {relational databaSeS}, and defining querieS on it. The main operationS of the relational algebra are the Set operationS (Such aSunion, interSection, and carteSian product), Selection (keeping only Some lineS of a table) and the projection (keeping only Some columnS). The relational data model deScribeS how the data iSStructured. Codd' S reduction algorithm can convert from {relational calculuS} to {relational algebra}. (1997-02-17)
