The Feature Data Objects (FDO) API provides access to data in a data store. A provider is a specific implementation of the FDO API that provides access to data in a particular data store. The FDO Provider for SDF provides FDO with access to an SDF-based data store.

The Autodesk SDF file format is a standalone, file-based spatial database format that supports multiple features classes and properties in a single file, and provides spatial indexing, interoperability, and high performance for large data sets.

The SDF file format has the following characteristics:

• SDF files can be read on different platforms.
• One schema in a single SDF file supports multiple feature classes.
• The SDF file has its own spatial indexing.
• SDF files can store geometric and non-geometric data with minimum overhead.
• The SDF file format supports a single writer at any time, with multiple readers.

An SDF schema can support the following:

• Auto ID generation
• Exclusive value range constraints
• Null value constraints
• Spatial contexts
• These geometry types: point, line string, polygon, multi-point, multi-line string, multi-polygon, curve string, curve polygon, multi-curve string, multi-curve polygon, linear ring, line string segment, circular arc segment, and ring.

For more information, see The Essential FDO (FET_TheEssentialFDO.pdf) and the FDO Developer's Guide (FDG_FDODevGuide.pdf).