Indexing and Querying Spatiotemporal Raster Data
Translated title
Indexing and Querying Spatiotemporal Raster Data
Term
2. term
Education
Publication year
2008
Submitted on
2008-06-12
Pages
24
Abstract
This paper addresses the issue of indexing and querying spatiotemporal raster data. This is done by developing a prototype named \apptitle{} that allows users to make queries on historical precipitation data, e.g., to determine the origin of water masses that has caused a flooding. Three functionally equivalent implementations have been developed. One is based on the GeoRaster component for Oracle Database, providing a performance baseline. Another is based on storing single pixel values along with their corresponding coordinates in a table. The last one is similar to the latter, but uses the Hilbert space-filling curve for indexing two-dimensional raster space. Among the key findings is that the Hilbert space-filling curve is not well-suited when raster data is sparse, nor when data is queried using small, non-rectangular search windows. Furthermore, the GeoRaster-based implementation has a storage requirement that is four times bigger compared to the other two, and a query performance that is slower by several orders of magnitude.
Keywords
Raster ; Hilbert ; IOT ; GeoRaster ; Range Query ; Space-filling curve ; kNN ; Sparse data
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