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EDBT
2012
ACM
247views Database» more  EDBT 2012»
6 years 6 months ago
Heuristics-based query optimisation for SPARQL
Query optimization in RDF Stores is a challenging problem as SPARQL queries typically contain many more joins than equivalent relational plans, and hence lead to a large join orde...
Petros Tsialiamanis, Lefteris Sidirourgos, Irini F...
EDBT
2011
ACM
281views Database» more  EDBT 2011»
7 years 7 months ago
Fast and accurate computation of equi-depth histograms over data streams
Equi-depth histograms represent a fundamental synopsis widely used in both database and data stream applications, as they provide the cornerstone of many techniques such as query ...
Hamid Mousavi, Carlo Zaniolo
SEMWEB
2010
Springer
8 years 2 months ago
SPARQL Query Optimization on Top of DHTs
We study the problem of SPARQL query optimization on top of distributed hash tables. Existing works on SPARQL query processing in such environments have never been implemented in a...
Zoi Kaoudi, Kostis Kyzirakos, Manolis Koubarakis
PVLDB
2008
126views more  PVLDB 2008»
8 years 3 months ago
Parallelizing query optimization
Many commercial RDBMSs employ cost-based query optimization exploiting dynamic programming (DP) to efficiently generate the optimal query execution plan. However, optimization tim...
Wook-Shin Han, Wooseong Kwak, Jinsoo Lee, Guy M. L...
VLDB
2002
ACM
126views Database» more  VLDB 2002»
8 years 3 months ago
Plan Selection Based on Query Clustering
Query optimization is a computationally intensive process, especially for complex queries. We present here a tool, called PLASTIC, that can be used by query optimizers to amortize...
Antara Ghosh, Jignashu Parikh, Vibhuti S. Sengar, ...
SIGMOD
2002
ACM
141views Database» more  SIGMOD 2002»
8 years 3 months ago
Bringing Order to Query Optimization
A variety of developments combine to highlight the need for respecting order when manipulating relations. For example, new functionality is being added to SQL to support OLAP-styl...
Giedrius Slivinskas, Christian S. Jensen, Richard ...
DPD
1998
117views more  DPD 1998»
8 years 3 months ago
Solving Local Cost Estimation Problem for Global Query Optimization in Multidatabase Systems
To meet users’ growing needs for accessing pre-existing heterogeneous databases, a multidatabase system (MDBS) integrating multiple databases has attracted many researchers recen...
Qiang Zhu, Per-Åke Larson
DEBU
2008
139views more  DEBU 2008»
8 years 4 months ago
Testing SQL Server's Query Optimizer: Challenges, Techniques and Experiences
Query optimization is an inherently complex problem, and validating the correctness and effectiveness of a query optimizer can be a task of comparable complexity. The overall proc...
Leo Giakoumakis, César A. Galindo-Legaria
SIGMOD
2010
ACM
208views Database» more  SIGMOD 2010»
8 years 4 months ago
Hierarchically organized skew-tolerant histograms for geographic data objects
Histograms have been widely used for fast estimation of query result sizes in query optimization. In this paper, we propose a new histogram method, called the Skew-Tolerant Histog...
Yohan J. Roh, Jae Ho Kim, Yon Dohn Chung, Jin Hyun...
IWMMDBMS
1998
139views more  IWMMDBMS 1998»
8 years 5 months ago
Fusion of Multimedia Information
: In recent years the fusion of multimedia information from multiple real-time sources and databases has become increasingly important because of its practical significance in many...
Shi-Kuo Chang, Taieb Znati
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