The complexity of evaluating relational queries
Information and Control
Incomplete Information in Relational Databases
Journal of the ACM (JACM)
Extending the database relational model to capture more meaning
ACM Transactions on Database Systems (TODS)
On Databases with Incomplete Information
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On the Complexity of Testing Implications of Functional and Join Dependencies
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PODS '85 Proceedings of the fourth ACM SIGACT-SIGMOD symposium on Principles of database systems
Principles of Database Systems
Principles of Database Systems
Computers and Intractability: A Guide to the Theory of NP-Completeness
Computers and Intractability: A Guide to the Theory of NP-Completeness
Database relations with null values
PODS '82 Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems
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VLDB '84 Proceedings of the 10th International Conference on Very Large Data Bases
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STOC '82 Proceedings of the fourteenth annual ACM symposium on Theory of computing
A Sound and Sometimes Complete Query Evaluation Algorithm for Relational Databases with Null Values
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PODS '89 Proceedings of the eighth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
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A family of incomplete relational database models
VLDB '89 Proceedings of the 15th international conference on Very large data bases
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An Exploration of Relationships Among Exclusive Disjunctive Data
IEEE Transactions on Knowledge and Data Engineering
Current Approaches to Handling Imperfect Information in Data and Knowledge Bases
IEEE Transactions on Knowledge and Data Engineering
A Hybrid Representation of Vague Collections for Distributed Object Management Systems
IEEE Transactions on Knowledge and Data Engineering
Incomplete Relational Database Models Based on Intervals
IEEE Transactions on Knowledge and Data Engineering
Offering a Precision-Performance Tradeoff for Aggregation Queries over Replicated Data
VLDB '00 Proceedings of the 26th International Conference on Very Large Data Bases
A Closed Approach to Vague Collections in Partly Inaccessible Distributed Databases
ADBIS '99 Proceedings of the Third East European Conference on Advances in Databases and Information Systems
STDBM '99 Proceedings of the International Workshop on Spatio-Temporal Database Management
OLAP over uncertain and imprecise data
VLDB '05 Proceedings of the 31st international conference on Very large data bases
OLAP over uncertain and imprecise data
The VLDB Journal — The International Journal on Very Large Data Bases
Efficient aggregation algorithms for probabilistic data
SODA '07 Proceedings of the eighteenth annual ACM-SIAM symposium on Discrete algorithms
Ranking queries on uncertain data: a probabilistic threshold approach
Proceedings of the 2008 ACM SIGMOD international conference on Management of data
Query answering techniques on uncertain and probabilistic data: tutorial summary
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ACM Transactions on Database Systems (TODS)
Clustering Uncertain Data Via K-Medoids
SUM '08 Proceedings of the 2nd international conference on Scalable Uncertainty Management
A logical account of uncertain databases based on linear logic
Proceedings of the 12th International Conference on Database Theory
Continuously monitoring top-k uncertain data streams: a probabilistic threshold method
Distributed and Parallel Databases
Modeling and querying possible repairs in duplicate detection
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Merging Sets of Taxonomically Organized Data Using Concept Mappings under Uncertainty
OTM '09 Proceedings of the Confederated International Conferences, CoopIS, DOA, IS, and ODBASE 2009 on On the Move to Meaningful Internet Systems: Part II
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The VLDB Journal — The International Journal on Very Large Data Bases
Reverse ranking query over imprecise spatial data
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The VLDB Journal — The International Journal on Very Large Data Bases
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SDM'10 Proceedings of the 7th VLDB conference on Secure data management
Foundations of uncertain-data integration
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Ranking queries on uncertain data
The VLDB Journal — The International Journal on Very Large Data Bases
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ADMA'10 Proceedings of the 6th international conference on Advanced data mining and applications: Part I
Efficient probabilistic reverse nearest neighbor query processing on uncertain data
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Probabilistic skylines on uncertain data: model and bounding-pruning-refining methods
Journal of Intelligent Information Systems
k-selection query over uncertain data
DASFAA'10 Proceedings of the 15th international conference on Database Systems for Advanced Applications - Volume Part I
Efficient processing of probabilistic set-containment queries on uncertain set-valued data
Information Sciences: an International Journal
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ADBIS'97 Proceedings of the First East-European conference on Advances in Databases and Information systems
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Computers & Mathematics with Applications
P-top-k queries in a probabilistic framework from information extraction models
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Wiley Interdisciplinary Reviews: Data Mining and Knowledge Discovery
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FARP: Mining fuzzy association rules from a probabilistic quantitative database
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Personal and Ubiquitous Computing
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Data & Knowledge Engineering
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We represent a set of possible worlds using an incomplete information database. The representation techniques that we study form a hierarchy, which generalizes relations of constants. This hierarchy ranges from the very simple Codd-table, (i e , a relation of constants and distinct variables called nulls, which stand for values present but unknown), to much more complex mechanisms involving views on conditioned-tables, (i e , queries on Codd-tables together with conditions). The views we consider are the queries that have polynomial data-complexity on complete information databases. Our conditions are conjunctions of equalities and inequalities.(1) We provide matching upper and lower bounds on the data-complexity of testing containement, membership, and uniqueness for sets of possible worlds and we fully classify these problems with respect to our representation hierarchy. The most surprising result in this classification is that it is complete in &Pgr;2p, whether a set of possible worlds represented by a Codd-table is a subset of a set of possible worlds represented by a Codd-table with one conjuction of inequalities.(2) We investigate the data-complexity of querying incomplete information databases. We examine both asking for certain facts and for possible facts. Our approach is algebraic but our bounds also apply to logical databases. We show that asking for a certain fact is coNP-complete, even for a fixed first order query on a Codd-table. We thus strengthen a lower bound of [16], who showed that this holds for a Codd-table with a conjunction of inequalities. For each fixed positive existential query we present a polynomial algorithm solving the bounded possible fact problem of this query on conditioned-tables. We show that our approach is, in a sense, the best possible, by deriving two NP-completeness lower bounds for the bounded possible fact problem when the fixed query contains either negation or recursion.