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PODS
2004
ACM
120views Database» more  PODS 2004»
14 years 10 months ago
Locally Consistent Transformations and Query Answering in Data Exchange
Data exchange is the problem of taking data structured under a source schema and creating an instance of a target schema. Given a source instance, there may be many solutions ? ta...
Marcelo Arenas, Pablo Barceló, Ronald Fagin...
PODS
2005
ACM
211views Database» more  PODS 2005»
14 years 10 months ago
Join-distinct aggregate estimation over update streams
There is growing interest in algorithms for processing and querying continuous data streams (i.e., data that is seen only once in a fixed order) with limited memory resources. Pro...
Sumit Ganguly, Minos N. Garofalakis, Amit Kumar, R...
PODS
2007
ACM
159views Database» more  PODS 2007»
14 years 10 months ago
Generalized hypertree decompositions: np-hardness and tractable variants
The generalized hypertree width GHW(H) of a hypergraph H is a measure of its cyclicity. Classes of conjunctive queries or constraint satisfaction problems whose associated hypergr...
Georg Gottlob, Thomas Schwentick, Zoltán Mi...
PODS
2008
ACM
165views Database» more  PODS 2008»
14 years 10 months ago
Data exchange and schema mappings in open and closed worlds
In the study of data exchange one usually assumes an openworld semantics, making it possible to extend instances of target schemas. An alternative closed-world semantics only move...
Leonid Libkin, Cristina Sirangelo
EDBT
2008
ACM
144views Database» more  EDBT 2008»
14 years 10 months ago
BI batch manager: a system for managing batch workloads on enterprise data-warehouses
Modern enterprise data warehouses have complex workloads that are notoriously difficult to manage. An important problem in workload management is to run these complex workloads `o...
Abhay Mehta, Chetan Gupta, Umeshwar Dayal