Skip to Main content Skip to Navigation
Conference papers

Answering Why-Not Questions

Nicole Bidoit 1, 2 Melanie Herschel 1, 2 Katerina Tzompanaki 1, 2
2 OAK - Database optimizations and architectures for complex large data
LRI - Laboratoire de Recherche en Informatique, UP11 - Université Paris-Sud - Paris 11, Inria Saclay - Ile de France, CNRS - Centre National de la Recherche Scientifique : UMR8623
Abstract : With the increasing amount of available data and transformations manipulating the data, it has become essential to analyze and debug data transformations. A sub-problem of data transformation analysis is to understand why some data are not part of the result of a relational query. One possibility to explain the lack of data in a query result is to identify where in the query data pertinent to the expected, but missing output is lost during query processing. A first approach to this so called why-not provenance has been recently proposed, but we show that this first approach has some shortcomings. To overcome these shortcomings, we propose an algorithm to explain non-existing data in a query result. This algorithm allows to compute the why-not provenance for rela- tional queries involving selection, projection, join and union. After providing necessary definitions, this paper contributes a detailed description of the algorithm. A comparative evaluation shows that it is both more efficient and effective than the state-of-the-art ap- proach.
Document type :
Conference papers
Complete list of metadata

Cited literature [19 references]  Display  Hide  Download
Contributor : Melanie Herschel Connect in order to contact the contributor
Submitted on : Thursday, March 20, 2014 - 4:38:14 PM
Last modification on : Thursday, July 8, 2021 - 3:48:25 AM
Long-term archiving on: : Friday, June 20, 2014 - 10:36:19 AM


Files produced by the author(s)


  • HAL Id : hal-00909214, version 1



Nicole Bidoit, Melanie Herschel, Katerina Tzompanaki. Answering Why-Not Questions. Bases de Données Avancées (BDA), 2013, Nantes, France. ⟨hal-00909214⟩



Les métriques sont temporairement indisponibles