(Presenting Fri. February 15, 2019) Query optimizers are fundamental components of database systems that are responsible for producing good execution plans. To navigate the search space of execution plans optimizers use transformation rules and a search strategy. Extending, maintaining and debugging a query optimizer entails understanding and modifying the library of rules. Today query optimizers use object-oriented languages to specify the valid transformation and search strategies which results in a sizable and complex codebase. In Hustle, a new database engine we are developing, our goal is to express the transformation rules in a Domain Specific Language to minimize the code complexity and produce a concise and maintainable query optimizer.
