Transcript Spatial Data Types

SQL/MM Spatial
Manage Spatial Data in an
ORDBMS
Knut Stolze
<[email protected]> IBM
Germany, 2003-02-26
Agenda
Overview
Spatial
Data Types & Methods
Information Schema
Demo
Questions
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
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
Overview (continued)
Store,
manage, and analyse
geometries as scalar (complex) values
Points, lines, and polygons
Collections
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
Spatial Data Types
ST_Geometry
ST_Surface
ST_Curve
ST_Point
ST_GeomCollection
ST_CurvePolygon
ST_MultiSurface
ST_MultiCurve
ST_Polygon
ST_MultiPolygon
ST_MultiLineString
ST_LineString
ST_CircularString
ST_CompoundCurve
ST_MultiPoint
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
Spatial Data Types
- Discussion - (continued)
Inconsistent
handling of empty geometries
Possible type hierarchy to address the
issues:
ST_Geometry
ST_MultiSurface
ST_MultiCurve
ST_MultiPolygon
ST_MultiCircString
ST_MultiLineString
ST_Polygon
ST_CircularString
ST_LineString
ST_MultiPoint
ST_Point
ST_Empty
Spatial Methods
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_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_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
ST_Distance
ST_Equals
ST_Relate
ST_Disjoint
ST_Intersects
ST_Touches
ST_Crosses
ST_Within
ST_Contains
ST_Overlaps
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
<gml:Point><gml:coord><gml:X>10</gml:X>
<gml:Y>10</gml:Y></gml:coord></gml:Point>
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
Information Schema
associat
ed
ST_GEOMETRY_
COLUMNS
ST_SPATIAL_
REFERENCE_SYSTEMS
is subset
ST_UNITS_OF_
MEASURE
COLUMNS
(SQL99)
ST_SIZINGS
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,
DEMO
Questions??