Database Systems (TODS)


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ACM Transactions on Database Systems (TODS), Volume 31 Issue 2, June 2006

Dynamic indexing for multidimensional non-ordered discrete data spaces using a data-partitioning approach
Gang Qian, Qiang Zhu, Qiang Xue, Sakti Pramanik
Pages: 439-484
DOI: 10.1145/1138394.1138395
Similarity searches in multidimensional Non-ordered Discrete Data Spaces (NDDS) are becoming increasingly important for application areas such as bioinformatics, biometrics, data mining and E-commerce. Efficient similarity searches require robust...

Maintenance of K-nn and spatial join queries on continuously moving points
Glenn S. Iwerks, Hanan Samet, Kenneth P. Smith
Pages: 485-536
DOI: 10.1145/1138394.1138396
Cars, aircraft, mobile cell phones, ships, tanks, and mobile robots all have the common property that they are moving objects. A kinematic representation can be used to describe the location of these objects as a function of time. For example, a...

Query optimization in distributed networks of autonomous database systems
Fragkiskos Pentaris, Yannis Ioannidis
Pages: 537-583
DOI: 10.1145/1138394.1138397
Large-scale distributed environments, where each node is completely autonomous and offers services to its peers through external communication, pose significant challenges to query processing and optimization. Autonomy is the main source of the...

Summarizing level-two topological relations in large spatial datasets
Xuemin Lin, Qing Liu, Yidong Yuan, Xiaofang Zhou, Hongjun Lu
Pages: 584-630
DOI: 10.1145/1138394.1138398
Summarizing topological relations is fundamental to many spatial applications including spatial query optimization. In this article, we present several novel techniques to effectively construct cell density based spatial histograms for range (window)...

Adaptive pull-based policies for wide area data delivery
Laura Bright, Avigdor Gal, Louiqa Raschid
Pages: 631-671
DOI: 10.1145/1138394.1138399
Wide area data delivery requires timely propagation of up-to-date information to thousands of clients over a wide area network. Applications include web caching, RSS source monitoring, and email access via a mobile network. Data sources vary widely...

Rewriting queries with arbitrary aggregation functions using views
Sara Cohen, Werner Nutt, Yehoshua Sagiv
Pages: 672-715
DOI: 10.1145/1138394.1138400
The problem of rewriting aggregate queries using views is studied for conjunctive queries with arbitrary aggregation functions and built-in predicates. Two types of queries over views are introduced for rewriting aggregate queries: pure...

Domain-independent data cleaning via analysis of entity-relationship graph
Dmitri V. Kalashnikov, Sharad Mehrotra
Pages: 716-767
DOI: 10.1145/1138394.1138401
In this article, we address the problem of reference disambiguation. Specifically, we consider a situation where entities in the database are referred to using descriptions (e.g., a set of instantiated attributes). The objective of reference...