Prioritized repairing and consistent query answering in relational databases
نویسندگان
چکیده
منابع مشابه
Certain Query Answering in Partially Consistent Databases
A database is called uncertain if two or more tuples of the same relation are allowed to agree on their primary key. Intuitively, such tuples act as alternatives for each other. A repair (or possible world) of such uncertain database is obtained by selecting a maximal number of tuples without ever selecting two tuples of the same relation that agree on their primary key. For a Boolean query q, ...
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For several reasons, databases may be inconsistent with respect to a set of integrity constraints. Those inconsistent states must be somehow resolved in order to be able to use the information stored in them. In some cases, data cleaning could be an approach to get rid of these inconsistencies. However, this may be a complex and nondeterministic process that may lead to the loss of potentially ...
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In its traditional definition, a repair of an inconsistent databaseis a consistent database that differs from the inconsistent onein a “minimal way.” Often, repairs are not equally legiti-mate, as it is desired to prefer one over another; for example,one fact is regarded more reliable than another, or a morerecent fact should be preferred to an earlier one. Motivatedby t...
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Optimizing the database queries is one of hard research problems. Exhaustive search techniques like dynamic programming is suitable for queries with a few relations, but by increasing the number of relations in query, much use of memory and processing is needed, and the use of these methods is not suitable, so we have to use random and evolutionary methods. The use of evolutionary methods, beca...
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A relational database is inconsistent if it does not satisfy a given set of integrity constraints. Nevertheless, it is likely that most of the data in it is consistent with the constraints. In this paper we apply logic programming based on answer sets to the problem of retrieving consistent information from a possibly inconsistent database. Since consistent information persists from the origina...
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ژورنال
عنوان ژورنال: Annals of Mathematics and Artificial Intelligence
سال: 2012
ISSN: 1012-2443,1573-7470
DOI: 10.1007/s10472-012-9288-8