Relational Query

• While SQL queries are implementation-agnostic, Relational Query operations also tell the DBMS how to get the information requested
• There exist also Tuple Relational Calculus and Domain Relational Calculus, but we won't meddle with those here

Relational Algebra

• Relational Algebra consists of sets, and operations performed on those set. It runs on six fundamental operators
  • select (\(\sigma\))
  • project (\(\pi\))
  • union (\(\cup\))
  • set difference (-)
  • cartesian product (\(X\))
  • rename (\(\rho\))