- Motivation
- SQL has simple atomic data-types, like integer, dates and string
- Not convenient for spatial data and queries
- Spatial data (e.g. polygons) is complex
- Spatial operation: topological, euclidean, directional, metric
- SQL 3 allows user defined data types and operations
- Spatial data types and operations can be added to SQL3
- Open Geodata Interchange Standard (OGIS)
- Half a dozen spatial data types
- Several spatial operations
- Supported by major vendors, e.g. ESRI, Intergraph, Oracle, IBM,...
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Última modificación: Thursday, 17 de November de 2005, 17:30