HOMES: A Higher-Order Mapping Evaluation System

We describe a system that integrates querying and query transformation in a single higher-order query language. The system allows users to write queries that integrate and combine query transformations. The power of higher-order functions also allows one to succinctly write complex relational queries. Our demonstration shows the utility of the system, explains the implementation architecture on top of a relational DBMS, and explains optimizations that combine subquery caching techniques from relational databases with sharing detection schemes from functional programming.