Although integrity constraints have long been used to maintain data consistency, there are situations in which they may not be enforced or satisfied. ConQuer is a system for efficient and scalable answering of SQL queries on databases that may violate a set of constraints. ConQuer permits users to postulate a set of key constraints together with their queries. The system rewrites the queries to retrieve all (and only) data that is consistent with respect to the constraints. The rewriting is into SQL, so the rewritten queries can be efficiently optimized and executed by commercial database systems.
Ariel Fuxman received the 2008 ACM SIGMOD Jim Gray Doctoral Dissertation Award for his work on this project.