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Results 1 - 10
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305
Query Optimization for XML
- In Proceedings of VLDB
, 1999
"... XML is an emerging standard for data representation and exchange on the World-Wide Web. Due to the nature of information on the Web and the inherent flexibility of XML, we expect that much of the data encoded in XML will be semistructured:the data may be irregular or incomplete, and its structu ..."
Abstract
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Cited by 208 (3 self)
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structure may change rapidly or unpredictably. This paper describes the query processor of Lore,aDBMS for XML-based data supporting an expressive query language. We focus primarily on Lore's cost-based query optimizer. While all of the usual problems associated with cost-based query optimization
Query by humming: musical information retrieval in an audio database
- In ACM Multimedia
, 1995
"... The emergence of audio and video data types in databases will require new information retrieval methods adapted to the specific characteristics and needs of these data types. An effective and natural way of querying a musical audio database is by humming the tune of a song. In this paper, a system f ..."
Abstract
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Cited by 233 (0 self)
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for querying an audio database by humming is described along with a scheme for representing the melodic information in a song as relative pitch changes. Relevant difficulties involved with tracking pitch are enumerated, along with the approach we followed, and the performance results of system indicating its
Crowdsourced Enumeration Queries
"... Abstract — Hybrid human/computer database systems promise to greatly expand the usefulness of query processing by incorporating the crowd for data gathering and other tasks. Such systems raise many implementation questions. Perhaps the most fundamental question is that the closed world assumption un ..."
Abstract
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Cited by 17 (3 self)
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Abstract — Hybrid human/computer database systems promise to greatly expand the usefulness of query processing by incorporating the crowd for data gathering and other tasks. Such systems raise many implementation questions. Perhaps the most fundamental question is that the closed world assumption
Constant delay enumeration for conjunctive queries
"... We survey some of the recent results about enumerat-ing the answers to queries over a database. We focus on the case where the enumeration is performed with a constant delay between any two consecutive solutions, after a linear time preprocessing. This cannot be always achieved. It requires restrict ..."
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We survey some of the recent results about enumerat-ing the answers to queries over a database. We focus on the case where the enumeration is performed with a constant delay between any two consecutive solutions, after a linear time preprocessing. This cannot be always achieved. It requires
On acyclic conjunctive queries and constant delay enumeration
- IN PROCEEDINGS OF THE 16TH EACSL ANNUAL CONFERENCE ON COMPUTER SCIENCE AND LOGIC (CSL 2007), LNCS 4646
, 2007
"... We study the enumeration complexity of the natural extension of acyclic conjunctive queries with disequalities. In this language, a number of NP-complete problems can be expressed. We first improve a previous result of Papadimitriou and Yannakakis by proving that such queries can be computed in ti ..."
Abstract
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Cited by 21 (8 self)
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We study the enumeration complexity of the natural extension of acyclic conjunctive queries with disequalities. In this language, a number of NP-complete problems can be expressed. We first improve a previous result of Papadimitriou and Yannakakis by proving that such queries can be computed
Efficient Enumeration for Conjunctive Queries over Xunderbar Structures
- in "19th EACSL Annual Conference on Computer Science Logic", Tchèque, République
, 2010
"... Abstract. We investigate efficient enumeration algorithms for conjunctive queries for databases over binary relations that satisfy the X property. Tree-like relations such as XPath axes or grids are natural examples of such relations. We first show that the result of an n-ary conjunctive query Q ove ..."
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Cited by 8 (2 self)
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Abstract. We investigate efficient enumeration algorithms for conjunctive queries for databases over binary relations that satisfy the X property. Tree-like relations such as XPath axes or grids are natural examples of such relations. We first show that the result of an n-ary conjunctive query Q
Enumeration of monadic second-order queries on trees
, 2013
"... We consider the enumeration problem of monadic second-order (MSO) queries with first-order free variables over trees. In [Bagan 2006] it was shown that this problem is in CONSTANT-DELAYlin. An enumeration problem belongs to CONSTANT-DELAYlin if for an input structure of size n it can be solved by: — ..."
Abstract
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Cited by 5 (4 self)
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We consider the enumeration problem of monadic second-order (MSO) queries with first-order free variables over trees. In [Bagan 2006] it was shown that this problem is in CONSTANT-DELAYlin. An enumeration problem belongs to CONSTANT-DELAYlin if for an input structure of size n it can be solved by
RankSQL: Query algebra and optimization for relational top-k queries
- In SIGMOD
, 2005
"... This paper introduces RankSQL, a system that provides a systematic and principled framework to support efficient evaluations of ranking (top-k) queries in relational database systems (RDBMS), by extending relational algebra and query optimization. Previously, top-k query processing is studied in the ..."
Abstract
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Cited by 110 (17 self)
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plans (that cannot be expressed traditionally) based on a fundamental ranking principle. To optimize top-k queries, we propose a dimensional enumeration algorithm to explore the extended plan space by enumerating plans along two dual dimensions: ranking and membership. We also propose a sampling
Enumerating with constant delay the answers to a query
"... We survey recent results about enumerating with constant delaytheanswerstoaqueryoveradatabase. More precisely, we focus on the case when enumeration can be achieved with a preprocessing running in time linear in the size of the database, followed by an enumeration process outputting the answers one ..."
Abstract
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Cited by 3 (1 self)
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We survey recent results about enumerating with constant delaytheanswerstoaqueryoveradatabase. More precisely, we focus on the case when enumeration can be achieved with a preprocessing running in time linear in the size of the database, followed by an enumeration process outputting the answers one
Results 1 - 10
of
305
