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About 6,953 papers for “query tree”

Query Tree

University Research Chair) · Encyclopedia of Database Systems · 2009

Cited by 0

PML Tree Query

Pajas, Petr, Štěpánek, Jan, Sedlák, Michal · Americanae (AECID Library) · 2013

System for querying annotated treebanks in PML format. The querying uses it own query language with graphical representation. It has two different implementations (SQL and Perl) and several clients (TrEd, browser-based, command line interface).

Cited by 0

PML Tree Query

Pajas, Petr, Štěpánek, Jan, Sedlák, Michal · Lindat/Clarin Repository (Lindat Clarin) · 2009

System for querying annotated treebanks in PML format. The querying uses it own query language with graphical representation. It has two different implementations (SQL and Perl) and several clients (TrEd, browser-based, command line interface).

Cited by 0

On Determining Tree Query Membership Of A Distributed Query

Clement Yu, Meral Özsoyoğlu · INFOR Information Systems and Operational Research · 1984

In processing distributed relational database queries, the cost of communication between sites is the dominant cost factor. It is generally agreed that the amount of data transferred determines this communication cost to a large extent. Thus it is desirable to minimize the amount of transmitted data.Semi-join is a relational database operator which can be utilized to reduce the amount of data transmission in processing distributed queries. A class of queries, called tree queries, can always be answered using semi-joins. In this paper an algorithm is presented which decides whether or not a query involvingjoin clauses with relational operators {<≥,≠,≡,≤,>} is a tree query. For any tree query the algorithm also produces a tree query graph, so that the sequences of semi-joins to answer the query can immediately be determined.

Cited by 27

An algorithm for tree-query membership of a distributed query

C. Yu, Meral Özsoyoğlu · 2005

The aim is to process distributed queries ef ficiently. The cost of communications between sites is dominant in processing such queries. It is assumed that the amount of data transferred determines the transmission cost to a large extent. Thus, it is desirable to minimize the amount of transmitted data. Bernstein-and Chiu [2] classified queries into two types: tree and cyclic queries. They defined an operation called semi-join which requires minimal transfer of data between sites. Then they showed that tree queries can always be answered by semi-joins but cyclic queries may not. An algorithm to decide whether a query is cyclic or not was presented in their paper. Their algorithm works when the number of domains in common between any two relations is no more than one. The aim of this paper is to generalize their algorithm. Specifically, we present a conceptionally simple algorithm which decides the type of a query when the number of domains in common between two relations may exceed one. An implementation of the algorithm is outlined. The algorithm runs in 0(max(e,e')) time and O(e) space complexity where e and e' are the number of edges in the transitive closure of the join graph and the query graph respectively.

Cited by 113

Kruskal's Algorithm for Query Tree Optimization

Pryscila Barvik Guttoski, Marcos Sfair Sunyé, Fabiano Silva · 2007

This paper describes an implementation of Kruskal's algorithm in query optimization process for generation of a near optimal execution query tree. The open source Post- greSQL DBMS was used in the experiments since its query optimization is performed by dynamic programming and genetic algorithm, which allows a concrete comparison with our approach. Kruskal's algorithm presents some advantages like its simplified code, its polynomial-time execution and the reduced search space to generate only one query tree, that will be the optimal tree. In most experiments, Kruskal's algorithm got the expected results in almost the same time as the results achieved by default Post- greSQL's optimization algorithms. The results confirm that Kruskal's algorithm is a feasible method for query optimization.

Cited by 23

Query Parsing Using Probabilistic Tree Grammars

F. Bernabeu, Jorge Calera-Rubio, M. I nesta et al. · 2012

The tree representation, using rhythm for dening the tree structure and pitch information for node labeling has proven to be effective in melodic similarity computation. In this paper we propose a solution representing melodies by tree grammars. For that, we infer a probabilistic context-free grammars for the melodies in a database, using their tree coding (with duration and pitch) and classify queries represented as a string of pitches. We aim to assess their ability to identify a noisy snippet query among a set of songs stored in symbolic format.

Cited by 0

Query Rewriting for Nondeterministic Tree Transducers

Kazuki Miyahara, Kenji Hashimoto, Hiroyuki Seki · IEICE Transactions on Information and Systems · 2016

We consider the problem of deciding whether a query can be rewritten by a nondeterministic view. It is known that rewriting is decidable if views are given by single-valued non-copying devices such as compositions of single-valued extended linear top-down tree transducers with regular look-ahead, and queries are given by deterministic MSO tree transducers. In this paper, we extend the result to the case that views are given by nondeterministic devices that are not always single-valued. We define two variants of rewriting: universal preservation and existential preservation, and discuss the decidability of them.

Cited by 0Open access

Query Parsing Using Probabilistic Tree Grammars

José F. Bernabeu, Jorge Calera-rubio, José M. Iñesta et al. · 2013

The tree representation, using rhythm for defining the tree structure and pitch information for node labeling has proven to be effective in melodic similarity computation. In this paper we propose a solution representing melodies by tree grammars. For that, we infer a probabilistic context-free grammars for the melodies in a database, using their tree coding (with duration and pitch) and classify queries represented as a string of pitches. We aim to assess their ability to identify a noisy snippet query among a set of songs stored in symbolic format. 1.

Cited by 0

Query parsing using probabilistic tree grammars

Bernabeu Briones, José Francisco, Calera Rubio, Jorge, Iñesta, José M. et al. · RUA, Repositorio Institucional de la Universidad de Alicante (Universidad de Alicante) · 2012

Appearing in Proceedings of the 29th International Conference on Machine Learning, Edinburgh, Scotland, UK, 2012.

Cited by 0Open access

Parallel Response Ternary Query Tree for

Rfid Tag Anti-collision, Ching-nung Yang, Song-ruei Cai et al. · 2015

A tag-collision (or missed reads) in RFID system (Radio Frequency Identification) system degrades the identification efficiency. The so-called tag collision is that a reader cannot identify a tag when more than one tags respond to a reader at the same time. There are some major anti-collision protocols on resolving tag collision, e.g., ALOHA-based protocol, binary tree protocol, and Query Tree (QT) protocol. Up to date, most tag anti-collision protocols are QT protocols. QT protocols are categorized into M-ary query tree (QT). In the previous literature, choosing M = 3 (i.e., a ternary QT (TQT)) was proven to have the optimum performance for tag identification. Recently, Yeh et al. used parallel response approach to reduce the number of collisions. In this paper, we combine the partial response and TQT to propose an effective parallel response TQT (PRTQT) protocol. Simu-lation results reveal that our PRTQT outperforms Yeh et al.’s protocol and TQT protocol.

Cited by 0

Keywords—XML, Tree Labeling, Query Processing.

S. Soltan, A. Zarnani, R. Alimohammadzadeh et al. · 2008

Abstract—XML has become a popular standard for information exchange via web. Each XML document can be presented as a rooted, ordered, labeled tree. The Node label shows the exact position of a node in the original document. Region and Dewey encoding are two famous methods of labeling trees. In this paper, we propose a new insert friendly labeling method named IFDewey based on recently proposed scheme, called Extended Dewey. In Extended Dewey many labels must be modified when a new node is inserted into the XML tree. Our method eliminates this problem by reserving even numbers for future insertion. Numbers generated by Extended Dewey may be even or odd. IFDewey modifies Extended Dewey so that only odd numbers are generated and even numbers can then be used for a much easier insertion of nodes.

Cited by 0

Skyline Query algorithm based on MB-tree

Runtao Liu, Xiaoxue Chen, Zhenguo Zhao · 2014

MB-tree, a new index structure for spatial data, its unique data partitioning method is the foundation of MBSQ algorithm proposed in this paper. Partition data space according to the x coordinate and y coordinate alternately until the number of data in each MBR is less than M. Using the dominance relationship between the point and MBR, the MBR and MBR, the middle nodes in the algorithm for skyline query are pruned effectively so that a large number of non-Skyline points can be excluded to improve the efficiency of the algorithm. A small amount of the remaining data points are calculated by using BNL algorithm to obtain the final Skyline set. Finally, the experimental results prove good efficiency and progressiveness of the MBSQ algorithm, and rapid query speed.

Cited by 2

GTQL : a query language for game tree

Jónheiður Ísleifsdóttir 1977- · Skemman · 2007

The search engines of high-performance game-playing programs are getting increasingly complicated as more and more enhancements get added. To maintain and further enhance such complex engines is an involved task, and the risk of introducing bugs or other unwanted behavior during modifications is substantial. In this thesis we introduce the Game Tree Query Language (GTQL), a query language specifically designed for game trees. The language can express queries about complex game-tree structures, including hierarchical relationships and aggregated attributes over subtree data. We also discuss the design and implementation of the Game Tree Query Tool (GTQT), software that allows efficient execution of GTQL queries on gametree logs. This tool helps program developers to gain added insight into the search process of their engines, as well as making regression testing easier. Empirical results are presented measuring the tool’s efficiency as well as its effectiveness in finding anomalies in large game trees.

Cited by 0Open access

On tree pattern query rewriting using views

Wang, Junhu, Yu, Jeffrey Xu, Liu, Chengfei · Figshare · 2007

We study and present our findings on two closely related problems on XPATH rewriting using views when both the view and the query are tree patterns involving /,// and []. First, given view V and query Q, is it possible for Q to have an equivalent rewriting using V which is the union of two or more tree patterns, but not an equivalent rewriting which is a single pattern? This problem is of both theoretical and practical importance because, if the answer is no, then, to answer a query completely using the views, we should use more efficient methods, such as the PTIME algorithm of [13], to find the equivalent rewriting, rather than try to find the union of all contained rewritings and test its equivalence to Q. Second, given a set V of views, we want to know under what conditions a subset V' of the views are redundant in the sense that for any query Q, the contained rewritings of Q using the views in V' are contained in those using the views in V-V'. Solving this problem can help us to, for example, choose the minimum number of views to be cached, or better design the virtual schema in a mediated data integration system, or avoid repeated calculation in query optimization. We provide necessary and sufficient conditions for the second problem, based on answers to the first problem. When the views produce comparable answers, we extend our findings to include the case where the intersection of views, in addition to the individual views, are used in the rewriting.

Cited by 0Open access