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JSS
2008
97views more  JSS 2008»
13 years 7 months ago
Proactive and reactive multi-dimensional histogram maintenance for selectivity estimation
Many state-of-the-art selectivity estimation methods use query feedback to maintain histogram buckets, thereby using the limited memory efficiently. However, they are "reacti...
Zhen He, Byung Suk Lee, Xiaoyang Sean Wang
ICDE
2003
IEEE
148views Database» more  ICDE 2003»
14 years 9 months ago
Efficient Computation of Subqueries in Complex OLAP
Expressing complex OLAP queries using group-by, aggregation, and joins can be extremely difficult. As a result of this, many alternate ways of expressing such queries have been de...
Michael H. Böhlen, Michael O. Akinde
ICDE
2005
IEEE
107views Database» more  ICDE 2005»
14 years 9 months ago
Venn Sampling: A Novel Prediction Technique for Moving Objects
Given a region qR and a future timestamp qT, a "range aggregate" query estimates the number of objects expected to appear in qR at time qT. Currently the only methods fo...
Yufei Tao, Dimitris Papadias, Jian Zhai, Qing Li
COMAD
2008
13 years 9 months ago
Concurrency Control in Distributed MRA Index Structure
Answering aggregate queries like sum, count, min, max over regions containing moving objects is often needed for virtual world applications, real-time monitoring systems, etc. Sin...
Neha Singh, S. Sudarshan
SIGMOD
2008
ACM
145views Database» more  SIGMOD 2008»
14 years 7 months ago
Optimizing complex queries with multiple relation instances
Today's query processing engines do not take advantage of the multiple occurrences of a relation in a query to improve performance. Instead, each instance is treated as a dis...
Yu Cao, Gopal C. Das, Chee Yong Chan, Kian-Lee Tan