Notes: Database Management Systems

• relational algebra <=> relational calculus
• procedural = imperative
• Datalog adds recursion which relational calculus can’t do
• check will be run for every DB update, so think carefully before adding check to database
• cannonical cover algorithm for functional dependencies(search about it)
• materialize
• extension language for SQL(PL/SQL, PL/pgSQL)
• Lossless joins; Dependency preservation; Redundancy Avoidance
• always close PreparedStatement and ResultSet for JDBC when working with Java, or you’ll get memory leak

• Calculate closures:

  • Attribute closures
  • Armstrong’s axioms
• 3NF? Didn’t mention it at all