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ICDT
2007
ACM
13 years 12 months ago
2007
ACM
Abstract. We study containment of conjunctive queries that are evaluated over databases that may contain tuples with null values. We assume the semantics of SQL for single block qu...
ICDT
2007
ACM
13 years 12 months ago
2007
ACM
We introduce a new abstract model of database query processing, finite cursor machines, that incorporates certain data streaming aspects. The model describes quite faithfully what...
ICDT
2007
ACM
13 years 12 months ago
2007
ACM
Abstract. A common approach to XML updates is to extend XQuery with update operations. This approach results in very expressive languages which are convenient for users but are dif...
ICDT
2007
ACM
13 years 12 months ago
2007
ACM
Query containment is a fundamental problem of databases. Given two queries q1 and q2, it asks whether the set of answers to q1 is included in the set of answers to q2 for any datab...
ICDT
2007
ACM
13 years 12 months ago
2007
ACM
Abstract. We define and study formal privacy guarantees for information integration systems, where sources are related to a public schema by mappings given by source-to-target dep...