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## First-Order Query Rewriting for Inconsistent Databases (2007)

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Citations: | 75 - 2 self |

### Citations

938 | Data Integration: A theoretical Perspective. In:
- Lenzerini
- 2002
(Show Context)
Citation Context ...pplications that have motivated the study of this problem include data integration and data exchange. Data integration is the problem of providing a unified view of data residing at different sources =-=[11]-=-. Data exchange is the problem of restructuring data residing under a source schema and creating an instance of a target schema that best represents the source data [7]. In both contexts, it is often ... |

552 | Answering queries using views: A survey
- Halevy
(Show Context)
Citation Context ...cations that have motivated the study of this problem include data integration and data exchange. In data integration, the goal is to provide “a uniform interface to multiple autonomous data sources” =-=[Hal01]-=-. In data exchange, “data structured under one (source) schema must be restructured and translated into an instance of a different (target) schema” [FKMP03]. In both contexts, it is often the case tha... |

410 | L.: Data exchange: Semantics and query answering
- Fagin, Kolaitis, et al.
- 2005
(Show Context)
Citation Context ...terface to multiple autonomous data sources” [Hal01]. In data exchange, “data structured under one (source) schema must be restructured and translated into an instance of a different (target) schema” =-=[FKMP03]-=-. In both contexts, it is often the case that the source data does not satisfy the integrity constraints of the global or target schema. The traditional approach to deal with this situation involves “... |

361 | Consistent Query Answers in Inconsistent Databases.
- Arenas, Bertossi
- 2003
(Show Context)
Citation Context ...e instance I over R. The database I might be inconsistent, in the sense that it might violate some of the constraints of Σ. In this work, we draw upon the concept of repairs, defined by Arenas et al. =-=[1]-=-, to give semantics to the problem. A repair I of I is an instance of R such that I satisfies the integrity constraints of Σ, and I differs minimally from I (where minimality is defined with respect t... |

305 | Complexity of answering queries using materialized views - Abiteboul, Duschka - 1998 |

283 | Elements of Finite Model Theory
- Libkin
- 2004
(Show Context)
Citation Context ...er rewritable iff q ∈ Cforest. Notice that Corollary 2 is a stronger result than Corollary 1 since it is well known that there are problems that are tractable but not expressible in first-order logic =-=[12]-=-. In particular, in previous work [8], we showed examples of queries (which are outside C ∗ ) for which the problem of obtaining consistent answers is tractable but not first-order rewritable. The int... |

267 |
On the structure of polynomial time reducibility
- Ladner
- 1975
(Show Context)
Citation Context ...at a query q is in class Chard if q ∈ C ∗ and q/∈ Cforest. Theorem 2. Let q be a query such that q ∈ Chard. Then, CONSISTENT(q, Σ) is coNP-complete in data complexity. In general, by Ladner’s Theorem =-=[10]-=-, there are classes of coNP problems for which there is no dichotomy between P and coNP-complete problems. However, this is not the case for the class of queries that is the focus of this section. In ... |

146 | On the Decidability and Complexity of Query Answering over Inconsistent and Incomplete Databases.
- Calì, Lembo
- 2003
(Show Context)
Citation Context ...ase. This potentially large number of repairs leads to the question of whether it is possible to compute consistent answers efficiently. The answer to this question is known to be negative in general =-=[4,6]-=-. However, this does not necessarily preclude the existence of classes of queries for which the problem is easier to compute. Hence, we consider the following question: for what queries is the problem... |

127 | Minimal-Change Integrity Maintenance Using Tuple Deletions
- Chomicki, Marcinkowski
- 2005
(Show Context)
Citation Context ...ase. This potentially large number of repairs leads to the question of whether it is possible to compute consistent answers efficiently. The answer to this question is known to be negative in general =-=[4,6]-=-. However, this does not necessarily preclude the existence of classes of queries for which the problem is easier to compute. Hence, we consider the following question: for what queries is the problem... |

82 | Query rewriting and answering under constraints in data integration systems
- Calì, Lembo, et al.
- 2003
(Show Context)
Citation Context ...ry answering literature is our focus on producing a first-order rewriting. Instead of rewriting into first-order formulas, most work in the literature is based on rewriting into logic programs (e.g., =-=[5]-=- and [3]). Their focus is on obtaining correct disjunctive logic programs for (usually large) classes of queries and constraints. However, given the high complexity of disjunctive logic programming, n... |

61 | Logic programs for consistently querying data integration systems
- Bravo, Bertossi
(Show Context)
Citation Context ...ring literature is our focus on producing a first-order rewriting. Instead of rewriting into first-order formulas, most work in the literature is based on rewriting into logic programs (e.g., [5] and =-=[3]-=-). Their focus is on obtaining correct disjunctive logic programs for (usually large) classes of queries and constraints. However, given the high complexity of disjunctive logic programming, none of t... |

54 |
der Meyden. Logical approaches to incomplete information
- van
- 1998
(Show Context)
Citation Context ...arge) classes of queries and constraints. However, given the high complexity of disjunctive logic programming, none of these approaches focus on tractability issues. The work on disjunctive databases =-=[13]-=- is relevant in our context. In particular, if Σ is a set of key dependencies, the set of all repairs of an inconsistent database can be represented as a disjunctive database D in such a way that each... |

37 | Data exchange: Semantics and query answering, Theoretical Computer Science 336 - Kolaitis, Popa - 2005 |

12 | Complexity tailored design: A new design methodology for databases with incomplete information
- Imielinski, Meyden, et al.
(Show Context)
Citation Context ... model of D. However, there are no results in the literature for first-order query rewriting over disjunctive databases. The only tractability results in this context have been given for OR-databases =-=[9]-=-, which are a restricted type of disjunctive databases. However, in general, given a database I possibly inconsistent with respect to a set of key dependencies, there may be no OR-database D such that... |

10 | Towards Inconsistency Management in Data Integration Systems
- Fuxman, Miller
- 2003
(Show Context)
Citation Context ...that Corollary 2 is a stronger result than Corollary 1 since it is well known that there are problems that are tractable but not expressible in first-order logic [12]. In particular, in previous work =-=[8]-=-, we showed examples of queries (which are outside C ∗ ) for which the problem of obtaining consistent answers is tractable but not first-order rewritable. The intractability of all queries in Chard w... |