Databases Reference
In-Depth Information
Multiple geometric forms are supported by the Oracle Spatial and Graph Option to
represent many different types of spatial data, including points and point clusters, lines
and line strings, polygons and complex polygons with holes, arc strings, line strings,
compound polygons, and circles. Oracle Database 12
c
adds support for nonuniform
rational B-spline (NURBS) curve geometries that allow representation of arbitrary
shapes. You can determine the interaction of these features through the use of operators
such as TOUCH, OVERLAP, INSIDE, and DISJOINT.
Data that shares the same object space and coordinates but represents different char‐
acteristics (such as physical and economic information) is often modeled in layers. Each
layer is divided into tiles representing smaller subareas within the larger area. A repre‐
sentation of this tile is stored with a spatial index that provides for quick lookups of
multiple characteristics in the same tile. The Spatial and Graph Option uses these rep‐
resentations to rapidly retrieve data based on spatial characteristics. For example, you
can perform a query against a physical area to examine where pollutants, minerals, and
water are present. Each of these characteristics is likely to be stored in a separate layer,
but they can be quickly mapped to their common tiles. The designers of these spatial-
based databases can increase the resolution of the maps by increasing the number of
tiles representing the geography.
The Spatial and Graph Option fully leverages Oracle's object features through the use
of a
spatial object type
that represents single or multi-element geometries. Spatial co‐
ordinates are stored in VARRAYs.
Support for GeoRaster data has existed since Oracle Database 10
g
and enables storing,
indexing, querying, analyzing, and delivering raster image data, associated spatial vector
geometry data, and metadata. This feature enables storage of multidimensional grid
layers and digital images in object-relational schema that are referenced to coordinate
systems. Oracle Database 11
g
added three-dimensional geometry objects and enhanced
Web Services support including business directory, Web Feature Service (WFS), Catalog
Services for the Web (CSW), and OpenLS support. Oracle Database 12
c
adds support
for raster algebraic expressions and analytics as well as support for advanced image
processing. Examples of the advanced image processing now supported include ad‐
vanced georeferencing, reprojection, rectification, orthorectification, raster update,
raster appending, large-scale physical mosaics, virtual mosaics, and ad hoc spatial quer‐
ies over virtual mosaics.
In the real world, most spatial implementations aren't custom-built from SQL, but in‐
stead utilize purchased GIS solutions that are built on top of databases. Many of these
GIS providers include Oracle Spatial and Graph Option technology as part of their
product bundles.
Support for the Network Data Model Graph was first added to this option in Oracle
Database 11
g
for defining and modeling of nodes, links, paths, subpaths, logical net‐
works (without geometric information), and spatial networks. Oracle Database 12
c
adds
