منابع مشابه
Intensional Answers to Database Queries
In addition to data, database systems store various on keys, integrity constraints, class hierarchies), are often kinds of information about their data. Examples are class hierarchies, to define the various data classes and their relationships; assumed as well, but little else is assumed. integrity constraints, to state required relationships among the Notable examples of this approach are the ...
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We consider information disclosure caused by answering queries to an XML database. We introduce an audit framework to determine ‘suspicious’ user queries, i.e. those queries that returned results being sufficient to derive disclosed secret information. We describe secret information in form of a secret query and provide a formal definition of ‘suspicious’ user queries based on what we call ‘rea...
متن کاملRC-Index: Diversifying Answers to Range Queries
Query result diversification is widely used in data exploration, Web search, and recommendation systems. The problem of returning diversified query results consists of finding a small subset of valid query answers that are representative and different from one another, usually quantified by a diversity score. Most existing techniques for query diversification first compute all valid query resul...
متن کاملRanking Approximate Answers to Semantic Web Queries
We consider the problem of a user querying semistructured data such as RDF without knowing its structure. In these circumstances, it is helpful if the querying system can perform an approximate matching of the user’s query to the data and can rank the answers in terms of how closely they match the original query. Our approximate matching framework allows us to incorporate standard notions of ap...
متن کاملExplaining Missing Answers to SPJUA Queries
This paper addresses the problem of explaining missing answers in queries that include selection, projection, join, union, aggregation and grouping (SPJUA). Explaining missing answers of queries is useful in various scenarios, including query understanding and debugging. We present a general framework for the generation of these explanations based on source data. We describe the algorithms used...
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ژورنال
عنوان ژورنال: American Journal of Physics
سال: 1995
ISSN: 0002-9505,1943-2909
DOI: 10.1119/1.17852