PVLDB
2010
13 years 10 months ago
2010
The need to improve a suboptimal execution plan picked by the query optimizer for a repeatedly run SQL query arises routinely. Complex expressions, skewed or correlated data, and ...
PVLDB
2008
13 years 12 months ago
2008
Given a parametrized n-dimensional SQL query template and a choice of query optimizer, a plan diagram is a color-coded pictorial enumeration of the execution plan choices of the o...
VLDB
2002
ACM
14 years 2 days ago
2002
ACM
The cost of a query plan depends on many parameters, such as predicate selectivities and available memory, whose values may not be known at optimization time. Parametric query opt...
DEBU
2000
14 years 7 days ago
2000
Execution plans produced by traditional query optimizers for data integration queries may yield poor performance for several reasons. The cost estimates may be inaccurate, the mem...
JCP
2007
14 years 10 days ago
2007
Abstract— Data synopsis is a lossy compressed representation of data stored into databases that helps the query optimizer to speed up the query process, e.g. time to retrieve the...
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...
SYRCODIS
2008
14 years 1 months ago
2008
In the last few years, XML became a de-facto standard for the exchange of structured and semi-structured data. The database research community took this development into account b...
DAWAK
2008
Springer
14 years 2 months ago
2008
Springer
Abstract. Data mining algorithms are often embedded in more complex systems, serving as the provider of data for internal decision making within these systems. In this paper we add...
VLDB
1991
ACM
14 years 4 months ago
1991
ACM
In order to cope efficiently with simple or complex queries as well as different application requirements (e.g., ad-hoc versus repetitive queries), a query optimizer ought to supp...
EDBTW
2006
Springer
14 years 4 months ago
2006
Springer
A data stream management system executes a large number of continuous queries in parallel. As stream characteristics and query workload change over time, the plan initially install...