Dominant skyline query processing

... Dominant Skyline Queries Dominant skyline queries are used to refine a large set of skyline points into a smaller and more interesting set of points Given a set of data records S, a skyline query ... Thick Skyline [11] Stable Skyline [8] Streaming Skyline [15] Overview Retrieve skyline points and their ε-neighbors Extend the expressiveness of standard skyline using EQU...

Ngày tải lên: 04/10/2015, 17:04

... Skyline query 50 100 price ($) 150 200 (b) Skyline of hotels Figure 1.1: Skyline example the example illustrates, skyline queries allow a user to specify his/her preferences directly in the query ... cheap hotels (preference for low values of Price) near to the beach (preference for low values of Distance) Figure 1.1(a) shows the skyline query while Figure 1.1(b) shows the...

Ngày tải lên: 16/09/2015, 15:54

... AmbientDB: relational query processing in a P2P network In Proceedings of the International Workshop on Databases, Information Systems and Peer-to-Peer Computing (DBISP2P), LNCS 2788, Springer Verlag ... Queries and Query Optimization in Schema-Based P2P- Systems In Proceedings of the International Workshop on Databases, Information Systems and Peer-to-Peer Computing (D...

Ngày tải lên: 19/02/2014, 12:20

... ii Parallel Query Processing Using Shared Memory Multiprocessors and Disk Arrays Wei Hong Computer Science Division Department of Electrical Engineering and Computer Science ... of database query processing is to nd the cheapest and fastest query plan 1.1.1 Conventional Query Processing Conventional query processing assumes a uniprocessor environment and...

Ngày tải lên: 28/04/2014, 13:32

... Objectives of query processing and optimization Static versus dynamic query optimization How a query is decomposed and semantically analyzed How to create a R.A.T to represent a query Rules of ... cost in query processing for centralized DBMS © Pearson Education Limited 1995, 2005 Query Processing Activities involved in retrieving data from the database Aims of QP: – transfo...

Ngày tải lên: 22/10/2014, 10:13

... challenges in distributed systems and provide background of complex query processing and failure recovery in distributed systems Finally, we outline the objectives of this thesis and provide an outline ... computation results In this thesis, we mainly focus on two challenging issues in distributed systems: complex query processing and fault tolerance 1...

Ngày tải lên: 08/09/2015, 15:18

... propose efficient location- based spatial keyword query processing strategies in this thesis First, we address a novel query, named mCK (m Closest Keywords) The query accepts a set of query keywords and ... address efficient location- based spatial keyword query processing strategies First, we introduce a novel query, named mCK, to locate m closest keywords in a spati...

Ngày tải lên: 10/09/2015, 08:26

... of PDMS Indexes (either local index or distributed index) are built to facilitate query processing A MetaStore is created to maintain the information of schema mapping, indexing and data distribution ... 2 Query Processing in Peer- to -Peer Based Data Management System Sai Wu School of Computing National University of Singapore Summary In last ten years, we have...

Ngày tải lên: 10/09/2015, 15:49

... of XML databases 2.1 Query processing over XML tree Twig pattern matching over tree-modeled XML data attracts the most research interests in XML query processing Generally, twig pattern matching ... Because in most algorithms, each relevant inverted list is scanned in a streaming fashion during query processing, inverted list in XML twig pattern query processin...

Ngày tải lên: 10/09/2015, 15:51

... unpredictable nature of the query environment, and deliver results progressively In order to support a high-level of interactivity during query processing, the study of progressive query processing techniques ... focused on the efficient processing of twig queries Our focus in the thesis is the progressive processing of XML joins, expressed using join predicates We classify exi...

Ngày tải lên: 11/09/2015, 09:06

... optimal query class is essentially enlarged 1.6 Contribution The main contributions of this thesis are in two areas: enhancement of the similarity query and the twig pattern query on XML data The contribution ... Representation of DOM Model of XML Data In order to research the characteristics of XML data, we need the formalized data model In this thesis, XML...

Ngày tải lên: 12/09/2015, 10:37

... 20 Human Motion Sequences 20 2.1.1 Feature extraction of human motion sequences 21 2.1.2 Matching human motion sequences 21 Distance Measures of Time ... the problems of efficient and effective query processing of complex spatio-temporal sequences Our solutions on subsequence matching and subsequence join techniques over human motion sequences can ......

Ngày tải lên: 14/09/2015, 14:05

... index structures for XML query processing Summary data, or histograms, on XML documents can provide critical information for query optimizers of XML databases Traditional histograms for relational ... keyword 15 XML Query VALUE Figure 1.1: An Example XML Data Model 1.2 The XPath Query Language A variety of query languages [1, 2, 3, 4, 5] have been proposed to query X...

Ngày tải lên: 16/09/2015, 17:11

... extra processing increase for cache miss, bottleneck occurring for single proxy cache, single point of failure for single proxy cache, and the reduction of hits to the original server For each ... presents an efficient updating method for the caches residing on the edge servers for maintaining cache coherence for multiple caches with data from a single source These caches...

Ngày tải lên: 16/09/2015, 17:12

... conventional data and social networking data is that conventional data focuses on entities and attributes, whereas social networking data focuses on entities and their inter-relationships Therefore, the ... models, query languages and access methods not offer adequate and native support for the representation, management, querying and especially inter-operabilit...

Ngày tải lên: 04/10/2015, 10:24