The Advanced Spatial Engine has several subcomponents that cater to the complex analysis and manipulation of spatial data that is required in traditional GIS applications. Internally, each of these additional components uses the underlying geometry data type and index and geometry engine functionality.

• The Network Data Model provides a data model for storing networks inside the Oracle database. Network elements (links and nodes) can be associated with costs and limits, for example, to model speed limits for road segments. Other functionality includes computation of the shortest path between two locations given a network of road segments, finding the N nearest nodes, and so on. The network data model is useful in routing applications. Typical routing applications include web services such as MapQuest and Yahoo! Maps, or navigation applications for roaming users using GPS technology. We cover more details about this component in Chapter 10.
• The Linear Referencing System (LRS) facilitates the translation of mile-markers on a highway (or any other linear feature) to geographic coordinate space and vice versa. This component allows users to address different segments of a linear geometry, such as a highway, without actually referring to the coordinates of the segment. This functionality is useful in transportation and utility applications, such as gas pipeline management.
• The Spatial Analysis and Mining Engine provides basic functionality for combining demographic and spatial analysis. This functionality is useful in identifying prospective sites for starting new stores based on customer density and income. These tools can also be used to materialize the influence of the neighborhood, which in turn can be used in improving the efficacy and predictive power of the Oracle Data Mining Engine.
• GeoRaster facilitates the storage and retrieval of georeferenced images using their spatial footprints and the associated metadata. GeoRaster defines a new data type for storing raster images of geographically referenced objects. This functionality is useful in the management of satellite imagery.
• The Topology Data Model supports detailed analysis and manipulation of spatial geometry data using finer topological elements such as nodes and edges. In some land-management applications, geometries share boundaries, as in the case of a property boundary and the road on which the property is situated. Oracle Spatial defines a new data type to represent topological elements (such as the shared "road segment") that can be shared between different spatial objects. Updates to shared elements implicitly define updates to the sharing geometry objects. In general, this component allows for the editing and manipulation of nodes and edges without disturbing the topological semantics of the application.

Oracle Spatial Technology Products

In the previous sections, we briefly described the functionality that Oracle Spatial provides to support the following operations on spatial data:

• Storage data model using the SDO_GEOMETRY data type
• Query and analysis using the Index Engine and Geometry Engine
• Location enabling using the geocoder by conversion of address data into SDO_GEOMETRY data
• Visualization using MapViewer
• Advanced Spatial Engine functionality such as network analysis

Let's next look at how this functionality is productized or licensed in Oracle Database 10g, version 10.1.0.2, and Oracle Application Server 10g, version 9.0.4. Note, though, that this packaging may change with later versions of Oracle.

MapViewer, the visualization tool of Spatial, is included as part of the Oracle Application Server. You can also deploy MapViewer by just installing the Oracle Containers for Java (OC4J) without installing the entire Application Server. We will look at these details in Chapter 11. The remainder of the Spatial functionality is included, sometimes optionally, with the Database Server. Let's look at these details next.

In the Lite edition of Oracle Database Server, none of the spatial functionality is included. As mentioned in an earlier Note, in the Personal, Standard,4 and Enterprise editions, a subset of the spatial functionality is included for free with the database. This subset is referred to as the Locator. In the Personal and the Enterprise Editions, the full functionality of spatial technology is available as a priced option, called Spatial. Let's look at each of these versions of Oracle Spatial and what you can do with them.