Spatial Context API

Feature Data Objects API

 
Spatial Context API
 
 
 

The following table defines default values for the spatial context properties for the providers (Oracle and SQL Server) that support the creation of a data store and an example set of spatial context properties extracted from an image file by the Raster provider.

Properties/Provider Oracle SQL Server Raster Notes
Coordinate system Cartesian Cartesian Cartesian  
Extent type Static Static Static 1
Extent Not NULL Not NULL Not NULL 2
Unit dimension XY XY XY 3
XY tolerance .001 .001 .001 4
Z tolerance .001 .001 .001 4
Active False False T 5
Note
  1. A static extent type means that the extent is defined at the time of the creation of the spatial context using the FdoICreateSpatialContext command. A dynamic extent type means that the extent may change as features are added so that it always encloses all of the features.
  2. The default extents expressed in AGF text format for the various providers are as follows:
    • Oracle and SQL Server: POLYGON ((-2000000 -2000000, 2000000 -2000000, 2000000 2000000, -2000000 2000000, -2000000 -2000000))
    • Raster: POLYGON ((-10000000 -10000000, 10000000 -10000000, 10000000 10000000, -10000000 10000000, -10000000 -10000000))
  3. The dimensionality is that of the extent. It is not set directly.
  4. See Tolerance.
  5. The Oracle and SQL Server providers can have multiple spatial contexts defined and can, therefore, show contexts in the reader that are not active.