Oracle Spatial Concepts

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• Oracle SpatialConcepts

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Concepts

• Geometric data types
• Oracle Spatial data model
• Spatial Layers
• Spatial query model
• Spatial indexing
• Window queries and join queries

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Types of Spatial Data
GIS (mapping) data
CAD data
CAM data
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Geometric Types

• Points (X1, Y1, Z1)
• Line Strings (X1, Y1, Z1, ...Xn, Yn, Zn)
• self-crossing lines are supported
• lines that close to form a ring have no implied
  interior
• straight, curved or mixed (compound) shapes

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Geometric Types (cont.)

• Polygons (X1, Y1, Z1, ... Xn, Yn, Zn)
• polygons are rotation independent outer rings
  must be counter clockwise, inner rings (voids)
  must be clockwise.
• coordinates must close and interior is implied
• interior area can be voided using additional
  elements (polygon with hole)
• self-crossing polygons are not supported
• straight, curved or mixed (compound) shapes

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Geometric Types
Compound line string
Arc line string
Optimized polygons
Compound polygon
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Geometric Representations

• Spatial attribute of a spatial feature geometric
  representation of its shape in some coordinate
  space
• Called geometry
• Oracle Spatial Object-Relational model represents
  geometries using tables with a single column of
  type MDSYS.SDO_GEOMETRY and a single row per
  geometry instance
• Relational model table with a predefined set of
  columns of type NUMBER and one or more rows for
  each geometry instance

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Spatial Data Model
Spatial layer
Geometries
Elements
Point
Line
Polygon
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Elements

• Basic building block of a geometry
• Element types
• Point
• Line
• Polygon
• Constructed using coordinates
• Limit on number of coordinates

Element 6
Element 5
Element 4
Element 2
Element 7
Element 1
Element 3
Hawaii, USA
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Geometry

• Represents a spatial feature
• Consists of an ordered set of primitive elements

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Layers

• Consist of geometries that share a common set of
  attributes
• A layer is a geometry column in a table

States layer