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FDO Architecture and Providers

Introduction

Developing Applications

 

Introduction > 

What Is a Provider?

A provider is a specific implementation of the FDO API. It is the software component that provides access to data in a particular data store.

For this release, the providers that are included are as follows:

• OsGeo FDO Provider for ArcSDE. Read/write access to feature data in an ESRI ArcSDE-based data store (that is, with an underlying Oracle or SQL Server database). Supports describing schema, and inserting, selecting, updating, and deleting feature data in existing schemas; does not support creating or deleting schemas.
• OsGeo FDO Provider for MySQL. Read/write access to feature data in a MySQL-based data store. Supports spatial data types and spatial query operations. A custom API can gather information, transmit exceptions, list data stores, and create connection objects. MySQL architecture supports various storage engines, characteristics, and capabilities.
• OsGeo FDO Provider for ODBC. Read/write access to feature data in an ODBC-based data store. Supports XYZ feature objects and can define feature classes for any relational database table with X, Y, and optionally Z columns; does not support creating or deleting schema. Object locations are stored in separate properties in the object definition.
• OsGeo FDO Provider for SDF. Read-write access to feature data in an SDF-based data store. Autodesk’s geospatial file format, SDF, supports multiple features/attributes, provides high performance for large data sets and interoperability with other Autodesk products, and spatial indexing. The SDF provider a valid alternative to database storage. Note that this release of the SDF provider supports version 3.0 of the SDF file format.
• OsGeo FDO Provider for SHP. Read/write access to existing spatial and attribute data in an ESRI SHP-based data store, which consists of separate shape files for geometry, index, and attributes. Each SHP and its associated DBF file is treated as a feature class with a single geometry property. This is a valid alternative to database storage but does not support locking.
• OsGeo FDO Provider for WFS. Read-only access to feature data in an OGC WFS-based data store. Supports client/server environment and retrieves geospatial data encoded in GML from one or more Web Feature Services sites. Client/server communication is encoded in XML with the exception of feature geometries, which are encoded in GML. Note that there is no public API documentation for this provider; all functionality is accessible via the base FDO API.
• OsGeo FDO Provider for WMS. Read-only access to feature data in an OGC WMS-based data store. Web Map Service (WMS) produces maps of spatially referenced data dynamically from geographic information, which are generally rendered in PNG, GIF, or JPEG, or as vector-based Scalable Vector Graphics (SVG) or Web Computer Graphics Metafile (WebCGM) formats.

FDO supports retrieval and update of spatial and non-spatial GIS feature data through a rich classification model that is based on OpenGIS and ISO standards.

An overview of the relationships between providers, data sources, data stores, and schemas is presented in the FDO Architecture and Providers graphic.

For more detailed information about the providers, see the appropriate appendix in this document. Data sources and data stores are discussed in the Establishing a Connection chapter. Schema concepts are discussed in the Schema Management chapter.