EDBT
2012
ACM
12 years 2 months ago
2012
ACM
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...
EDBT
2011
ACM
13 years 3 months ago
2011
ACM
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 ...
SEMWEB
2010
Springer
13 years 10 months ago
2010
Springer
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...
PVLDB
2008
13 years 12 months ago
2008
Many commercial RDBMSs employ cost-based query optimization exploiting dynamic programming (DP) to efficiently generate the optimal query execution plan. However, optimization tim...
VLDB
2002
ACM
14 years 1 days ago
2002
ACM
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...
SIGMOD
2002
ACM
14 years 2 days ago
2002
ACM
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...
DPD
1998
14 years 3 days ago
1998
To meet users’ growing needs for accessing pre-existing heterogeneous databases, a multidatabase system (MDBS) integrating multiple databases has attracted many researchers recen...
DEBU
2008
14 years 15 days ago
2008
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...
SIGMOD
2010
ACM
14 years 18 days ago
2010
ACM
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...
IWMMDBMS
1998
14 years 1 months ago
1998
: 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...