1. SQL/MM Spatial Manage Spatial Data in an ORDBMS Knut Stolze IBM Germany, 2003-02-26

2. Agenda  Overview  Spatial Data Types & Methods  Information Schema  Demo  Questions

3. Overview  Part 3 of SQL/MM  Part 1 - Framework  Part 2 - Full Text  Part 3 - Spatial  Part 5 - Still Image  Part 6 - Data Mining  Derived from OGC Simple Feature Specification for SQL  Currently: progressed to FDIS  IS expected for the end of the year

4. Overview (continued)  Based on SQL-99  Structured types, methods,...  The standard does not define:  Indexing mechanisms  Implementation issues  number, names, and types of attributes of the types  specific algorithms ƒ Follows the SQL99 approach

5. Overview (continued)  Store, manage, and analyse geometries as scalar (complex) values  Points, lines, and polygons  Collections

6. Overview (continued)  Primary application today: Geographic Information Systems (GIS)  Only sparse integration into classical database applications  Products:  IBM DB2 Spatial Extender  IDS Spatial DataBlade  Oracle Spatial

7. Spatial Data Types ST_SurfaceST_Curve ST_CurvePolygon ST_Polygon ST_MultiPolygon ST_MultiSurfaceST_MultiCurveST_MultiPoint ST_MultiLineString ST_GeomCollectionST_Point ST_LineString ST_CircularStringST_CompoundCurve ST_Geometry

8. Spatial Data Types - Discussion -  Attempt to implement Composite Design Pattern  originated from OGC class hierarchy  pattern cannot be implemented in SQL  ST_Point unrelated to ST_MultiPoint, ST_LineString unrelated to ST_MultiLineString, ST_Polygon unrelated to ST_MultiPolygon  further processing of results results oftentimes in more complex SQL  Types not properly mirrored between single-part and multi-part subtrees of the hierarchy

9. Spatial Data Types - Discussion - (continued) ST_MultiSurface ST_MultiPolygon ST_Polygon ST_MultiCurve ST_MultiCircStringST_MultiLineString ST_CircularString ST_LineString ST_MultiPoint ST_Point ST_Geometry ST_Empty  Inconsistent handling of empty geometries  Possible type hierarchy to address the issues:

10. Spatial Methods ST_Dimension ST_CoordDim ST_GeometryType ST_SRID ST_IsEmpty ST_IsSimple ST_IsValid ST_Boundary ST_Envelope ST_ConvexHull ST_Buffer ST_Intersection ST_Union ST_Difference ST_SymDifference ST_X ST_Y ST_Distance ST_Equals ST_Relate ST_Disjoint ST_Intersects ST_Touches ST_Crosses ST_Within ST_Contains ST_Overlaps ST_Geometry ST_Point ST_LineString ST_CircularString ST_CompoundCurve ST_CurvePolygon ST_Polygon ST_GeomCollection ST_MultiPoint ST_MultiLineString ST_MultiPolygon ST_AsText ST_AsBinary ST_AsGML ST_Transform ST_Length ST_StartPoint ST_EndPoint ST_IsClosed ST_IsRing ST_NumPoints ST_PointN ST_NumCurves ST_CurveN ST_Area ST_Perimeter ST_Centroid ST_PointOnSurface ST_ExteriorRing ST_InteriorRings ST_NumInteriorRing ST_InteriorRingN

11. Spatial Methods - Format Conversion -  Well-known Text Representation  point (10 10)  multipolygon (((1 1, 2 2, 1 2, 1 1)),((10 10, 10 20, 20 20, 20 10, 10 10)))  Well-known Binary Representation  x'01010000000000000000002440000000000000244 0'  Geography Markup Language  10 10  (Additional formats in products, e.g. Shape format)

12. Spatial Data Methods - Discussion -  Duplicated functionality  ST_Overlaps, ST_Intersects, ST_Crosses  ST_GeometryType & SPECIFIC_TYPE (SQL99)  Additional functionality already supported by products:  ST_ShortestPath (in current WD)  Z/M coordinate support  Other external data representations  ST_Generalize to simplify geometries

13. Information Schema COLUMNS (SQL99) ST_SPATIAL_ REFERENCE_SYSTEMS ST_UNITS_OF_ MEASURE ST_SIZINGS ST_GEOMETRY_ COLUMNS is subset associat ed

14. Information Schema - Discussion -  Merge ST_SIZINGS view with SIZINGS (SQL99)  additional facilities in SQL99 needed, first  ST_SPATIAL_REFERENCE_SYSTEMS is rather primitive, EPSG uses:  Coordinate Axis Name, Coordinate Axis, Coordinate System, Coordinate Reference System, Coordinate Operation, Ellipsoid, Datum, Prime Meridian, Coord_Op Method, Coord_Op Parameter, Coord_Op Parameter Usage, Coord_Op Parameter Value, Coord_Op Path

15. DEMO

16. Questions??