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
- 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.
- 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))
- The dimensionality is that of the extent. It is not set directly.
- See Tolerance.
- The Oracle and SQL Server providers can have multiple spatial contexts defined and can, therefore, show contexts in the reader that are not active.