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On the representation and querying of sets of possible worlds

Serge Abiteboul, Paris Kanellakis, Gösta Grahne
1991 Theoretical Computer Science  
Kanellakis and G. Grahne, On the representation and querying of sets of possible worlds, Theoretical Computer Science 78 (1991) 159-187.  ...  and uniqueness for sets of possible worlds.  ...  A central computational problem is the containment problem: "is a set of possible worlds a subset of another set of possible worlds?"  ... 
doi:10.1016/0304-3975(51)90007-2 fatcat:ns2mykvp6jfz7nwdagvve3hkpm

On the representation and querying of sets of possible worlds

Serge Abiteboul, Paris Kanellakis, Gosta Grahne
1987 SIGMOD record  
Permission to copy wIthout fee all or part of this materml IS granted provided that the copies are not made or dlstrlbuted for direct commercial advantage, the ACM copyright notlce and the title of the  ...  pubhcatlon and its date appear, and notlce IS given that copying IS by permlsslon of the Assoclatlon for Computmg Machmery To copy otherwlse, or to republish, requires a fee and/or specfic permisslon  ...  a set of tuples and given a set of possible worlds, IS there a possible world where slmllarltles between the posslblhty and the membership problems, because the size of the given set of tuples for posslblhty  ... 
doi:10.1145/38714.38724 fatcat:tqmg4lo3s5hkxjooeu6fknyk4e

From complete to incomplete information and back

Lyublena Antova, Christoph Koch, Dan Olteanu
2007 Proceedings of the 2007 ACM SIGMOD international conference on Management of data - SIGMOD '07  
The language supports the contemplation on alternatives and can thus map from a complete database to an incomplete one comprising several possible worlds.  ...  We argue that query languages with explicit constructs for handling uncertainty allow for the more natural and simple expression of many real-world decision support queries.  ...  This differs from the approach where a query can access the worlds "from outside", and preserves the spirit of traditional query processing on sets of possible worlds.  ... 
doi:10.1145/1247480.1247559 dblp:conf/sigmod/AntovaKO07 fatcat:xakzybnl4baorhns6k4gbfqage

Fast and Simple Relational Processing of Uncertain Data

Lyublena Antova, Thomas Jansen, Christoph Koch, Dan Olteanu
2008 2008 IEEE 24th International Conference on Data Engineering  
on the U-relational representation.  ...  The translation scheme essentially preserves the size of the query in terms of number of operations and, in particular, number of joins.  ...  for finite sets of possible worlds, that is, they allow for the representation of any finite world-set. • Succinctness: U-relations represent uncertainty on the attribute level.  ... 
doi:10.1109/icde.2008.4497507 dblp:conf/icde/AntovaJKO08 fatcat:iepsy7lft5e5bbcpa2dn4aqm2m

10^(10^6) Worlds and Beyond: Efficient Representation and Processing of Incomplete Information [article]

Lyublena Antova, Christoph Koch, Dan Olteanu
2008 arXiv   pre-print
WSDs are therefore a strong representation system for any relational query language. We study the problem of efficiently evaluating relational algebra queries on sets of worlds represented by WSDs.  ...  We introduce world-set decompositions (WSDs), a space-efficient formalism for representing any finite set of possible worlds over relational databases.  ...  We also develop a number of optimizations and techniques for normalizing the data representations obtained by queries to support scalable query processing even on very large world-sets. • We describe a  ... 
arXiv:cs/0606075v2 fatcat:avx7g62vavd3vmnlfuatlivznq

Fast and Simple Relational Processing of Uncertain Data [article]

Lyublena Antova, Thomas Jansen, Christoph Koch, Dan Olteanu
2007 arXiv   pre-print
on the U-relation representation.  ...  The translation scheme essentially preserves the size of the query in terms of number of operations and, in particular, number of joins.  ...  Given a set of possible worlds, we call a tuple certain iff it occurs in each of the worlds.  ... 
arXiv:0707.1644v1 fatcat:lexumg4ttzhcnfgwogp6wibwgi

10106Worlds and Beyond: Efficient Representation and Processing of Incomplete Information

Lyublena Antova, Christoph Koch, Dan Olteanu
2007 2007 IEEE 23rd International Conference on Data Engineering  
WSDs are therefore a strong representation system for any relational query language. We study the problem of efficiently evaluating relational algebra queries on sets of worlds represented by WSDs.  ...  We introduce world-set decompositions (WSDs), a space-efficient formalism for representing any finite set of possible worlds over relational databases.  ...  A fundamental assumption of this work is that one wants to store and manage sets of possible worlds.  ... 
doi:10.1109/icde.2007.367906 dblp:conf/icde/AntovaKO07 fatcat:b3ranizsgrdmrirebmb6r7xe6e

$${10^{(10^{6})}}$$ worlds and beyond: efficient representation and processing of incomplete information

Lyublena Antova, Christoph Koch, Dan Olteanu
2009 The VLDB journal  
WSDs are therefore a strong representation system for any relational query language. We study the problem of efficiently evaluating relational algebra queries on sets of worlds represented by WSDs.  ...  We introduce world-set decompositions (WSDs), a space-efficient formalism for representing any finite set of possible worlds over relational databases.  ...  A fundamental assumption of this work is that one wants to store and manage sets of possible worlds.  ... 
doi:10.1007/s00778-009-0149-y fatcat:c5hhkoxjlrgufbji2aj42d7gey

MayBMS: Managing Incomplete Information with Probabilistic World-Set Decompositions

Lyublena Antova, Christoph Koch, Dan Olteanu
2007 2007 IEEE 23rd International Conference on Data Engineering  
Some features of MayBMS are • Completeness of the representation system for finite world-sets. • Space-efficient representation of large world-sets. • Scalable evaluation and support for full relational  ...  algebra queries. • Probabilistic extension of the representation system and the query language.  ...  query evaluation on world-sets is to evaluate the query in each of the worlds.  ... 
doi:10.1109/icde.2007.369042 dblp:conf/icde/AntovaKO07a fatcat:53jzrc7tnncbbglb6puwrdzvga

Managing Probabilistic Data with MystiQ: The Can-Do, the Could-Do, and the Can't-Do [chapter]

Christopher Re, Dan Suciu
2008 Lecture Notes in Computer Science  
The MayBMS project has focused on representation problems, query language design, and query evaluation [3, 4, 2, 20] . Other  ...  Related Work Our research has focused primarily on SQL query evaluation and on views. Other groups have studied different aspects of probabilistic or incomplete databases.  ...  The schema of the probabilistic table is the same as that of the deterministic table from which it is derived, and its semantics is a set of possible worlds: each subset of table-name is a possible world  ... 
doi:10.1007/978-3-540-87993-0_3 fatcat:h4xoijkrvjfrlilkbfth5nictm

Quality Measures in Uncertain Data Management [chapter]

Ander de Keijzer, Maurice van Keulen
2007 Lecture Notes in Computer Science  
Some examples are applications dealing with sensor information, data integration applications and healthcare applications.  ...  A possible world is a possible representation of the real world and is constructed by taking one possibility or alternative for each of the real world objects.  ...  Let H be the set of correct answers to a query (as determined by a human), A the set of answers (the elements of the amalgamated query answer), and C the intersection of the two, i.e., the set of correct  ... 
doi:10.1007/978-3-540-75410-7_8 fatcat:ftmqbfucg5endhkjkqvcpetl7u

On Query Algebras for Probabilistic Databases

Christoph Koch
2009 SIGMOD record  
Content of this article. As a core algebra, we present probabilistic world-set algebra (WSA), origi-  ...  We give a formal definition of this language and illustrate it by examples. We then proceed to surveying the current state of knowledge regarding the expressive power and complexity of this core.  ...  The operation partitions the set of possible worlds into the groups of those worlds that agree on π A (Q). The result in each world is the set of tuples possible in Q within the world's group.  ... 
doi:10.1145/1519103.1519116 fatcat:ex2el4xphvdzdo6hjxvqgmgnne

A possible world approach to uncertain relational data

A. de Keijzer, M. van Keulen
2004 Proceedings. 15th International Workshop on Database and Expert Systems Applications, 2004.  
It appears that thinking in terms of 'possible worlds' is powerful in determining the proper semantics of these query primitives.  ...  We define a probabilistic relational data model and review standard SQL query primitives in the light of probabilistic data.  ...  The set of tuples representing one possibility for each real world object is called a possible world pW ⊆ pR, defined by 1. (∀v ∈ D k pR) • |Π v (pW )| = 1 2.  ... 
doi:10.1109/dexa.2004.1333596 dblp:conf/dexaw/KeijzerK04 fatcat:d4jklgqr55bnvcn637ncfpbdne

Uncertain Groupings: Probabilistic Combination of Grouping Data [chapter]

Brend Wanders, Maurice van Keulen, Paul van der Vet
2015 Lecture Notes in Computer Science  
A bio-informatician has a large number of homology data sources to choose from. To enable querying combined knowledge contained in these sources, they need to be integrated.  ...  We validate our approach by integrating three real-world biological databases on homology in three iterations.  ...  Acknowledgements We would like to thank the late Tjeerd Boerman for his work on the use case and his initial concept of groupings.  ... 
doi:10.1007/978-3-319-22849-5_17 fatcat:hbekaz3nffe4di6hqxcox6ufh4

World-set Decompositions: Expressiveness and Efficient Algorithms [article]

Dan Olteanu and Christoph Koch and Lyublena Antova
2008 arXiv   pre-print
The ability to represent large sets of possible instances (worlds) while supporting efficient storage and processing is an important challenge in this context.  ...  For possibly infinite world-sets, we show that a natural generalization of WSDs precisely captures the expressive power of c-tables.  ...  The recurrence relation for the time complexity is then (for sufficiently large constant a; n is the size of S and m is the arity of S) Acknowledgments.  ... 
arXiv:0705.4442v2 fatcat:lxycmuem6fdn5intgpswof2yq4
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