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Relational Algebra

  • The fundamental operations on tables (relations).
  • Underlies the semantics of SQL.
  • The basis of query optimization.

Algebra

  • A set of operations on values of some type, which yield values of the same type.
  • E.g. , , , and .
  • Numbers → numbers.

Relational Algebra

  • An algebra for relations, (i.e. tables).
  • Set-oriented: a relation is a set.

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