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 as union, 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 is struCtured. Codd' s reduCtion algorithmCan Convert from {relational CalCulus} to {relational algebra}. (1997-02-17)
