Query Optimiser

This project includes a Query Optimizer and an Estimator, that were built for SJDB (A MySQL like database designed by Dr Nicholas Gibbins)

• The Estimator: src/sjdb/Estimator.java accepts a database logical query and estimates the total cost in terms of disk accesses
• The Optimizer: src/sjdb/Optimiser.java optimises a given query by pushing down the Selects, creating Joins and adding Projects