Section: Scientific Foundations

Data Transformation Management

With the increasing complexity of data processing queries, for instance in applications such as relational data analysis or integration of Web data (e.g., XML or RDF) comes the need to better manage complex data transformations. This includes systematically verifying, maintaining, and testing the transformations an application relies on. In this context, Oak has focused on verifying the semantic correctness of a declarative program that specifies a data transformation query, e.g., an SQL query. To this end, we have investigated how to leverage data provenance (the information of the origin of data and the query operators) for query debugging. More specifically, we developed and implemented algorithms to explain unexpected results produced by a query (why-provenance) as well as expected results that are however missing from the query result (why-not provenance). Results have been presented in form of a software prototype [15] .