12,348 research outputs found
The Impact of Global Clustering on Spatial Database Systems
Global clustering has rarely been investigated in
the area of spatial database systems although dramatic
performance improvements can be
achieved by using suitable techniques. In this paper,
we propose a simple approach to global clustering
called cluster organization. We will demonstrate
that this cluster organization leads to considerable
performance improvements without any
algorithmic overhead. Based on real geographic
data, we perform a detailed empirical performance
evaluation and compare the cluster organization
to other organization models not using global
clustering. We will show that global clustering
speeds up the processing of window queries as
well as spatial joins without decreasing the performance
of the insertion of new objects and of selective
queries such as point queries. The spatial
join is sped up by a factor of about 4, whereas
non-selective window queries are accelerated by
even higher speed up factors
A storage and access architecture for efficient query processing in spatial database systems
Due to the high complexity of objects and queries and also due to extremely
large data volumes, geographic database systems impose stringent requirements on their
storage and access architecture with respect to efficient query processing. Performance
improving concepts such as spatial storage and access structures, approximations, object
decompositions and multi-phase query processing have been suggested and analyzed as
single building blocks. In this paper, we describe a storage and access architecture which
is composed from the above building blocks in a modular fashion. Additionally, we incorporate
into our architecture a new ingredient, the scene organization, for efficiently
supporting set-oriented access of large-area region queries. An experimental performance
comparison demonstrates that the concept of scene organization leads to considerable
performance improvements for large-area region queries by a factor of up to 150
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