Spatial DBMS
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Transcript of Spatial DBMS
Spatial DBMSSpatial Database Management Systems
IntroductionSDBMS is a database system with additional capabilities for handling spatial data.• Spatial Objects• Consist of points, lines, surfaces, volumes and higher
dimension objects that are used in applications of computer-aided design, cartography, geographic information systems.
• Spatial Data• The values of the objects’ spatial attributes: length,
configuration, perimeter, area, volume, etc.• Spatial Databases• A collection of spatial and non-spatial data that is
interrelated, of data descriptions and links between data
March 2002
April 2004
Functionality
• Spatial data is comprised of objects in multi-dimensional space• Spatial Indexing• Retrieving objects in a particular area without
scanning the entire space• Spatial Joins• Efficient algorithms for joining multiple spatial
objects
Raster and Vector Data
• Two very different types of data• Vector is spit into three primary
types: • polygon, line, point
• Raster data represents the fourth type of feature: surfaces• Eg: thematic data, spectral data,
and pictures (imagery)
Spatial Relationships
• Topological relationships• Eg: adjacent, in, touch, equal, cover, overlap, disjoint, etc.
• Direction relationships• Eg: above, below, north of, southeast of, etc.
• Metric relationships• Eg: distance, size, perimeter, etc.
Querying
• Spatial Selection• Eg: “All rivers in Arkansas” or “All rivers
within 50 miles of Little Rock”• Spatial Join• Eg: “For each river in Arkansas, find all
cities within 20 miles”
Indexing
• Organized so that only parts of the objects need to be examined to answer a query• Data stored as either points or polygons• Query types for points:• All points within a rectangle, point closest to query point,
find points matching x in increasing distance from query point
• Query types for polygons:• Intersection• Containment