Kedar Gawande Position Paper ITK 478 Fall / 04 / 2006

 Background for Topic Selection  Success & Penetration of OO Methodologies  Inherent Limitations in Relational DBMS  Increasing Migration towards Object based Technologies in the relational world

 King County, WA - Homeland Security Public Safety Portal Development  Utah Department of Transportation (UDOT) Oracle Spatial Transportation Asset Management  Bay Area Geological Hazard Abatement Districts use GIS Mashup to Identify and Manage Critical Data

 GIS,GPS, CAD, CAM, Multimedia Information Systems, Image Processing  Data management & processing needs  Size, complexity of applications  Needs translate into requirements for a DBMS

 Representation of space & elements within space  Real World Entities & its Spatial Representation  City, Street Intersection  Streets, River, Boundary  County, State, Parks,  Sample Queries  List all Emergency Exits within STV & Directions to the closest one from STV 108  Find length of a river within a state

 Consider a spatial dataset with:  County boundary (dashed white line)  Census block - name, area, population, boundary (dark line)  Water bodies (dark polygons)  Satellite Imagery (gray scale pixels)  Storage in a SDBMS table: create table census_blocks ( name string, area float, population number, boundarypolygon );

 Spatial DB features:  Spatial Model  Spatial ADTs ( Abstract Data types)  Spatial Operations like distance, overlap  Spatial Querying like Spatial Join  Spatial Indexing

Find Name & Area of Districts with Area more than 500 sq miles & find name and length of rivers that flow through that county.  Select C.name, C.district.name, C.district.Area(), R.name, R.length() from County C where C.district.Area() > 500 AND overlap(C, R) C.NameC.district.nameC.district.Area()R.NameR.Length() McLeanUniversity Niagara

 User Defined Data Types – If you can see it, you can model it  User defined Behavior – Different for different types of shapes in space  Inheritance – Polygon for city can inherit from polygon for state  Additional geometric types than relational  Enhanced Querying – If you can think it, you can query it  Spatial Indexing improves performance

 Why not RDBMS ?  Primitive data types – number, string etc  Cannot model spatial objects on these data types  Limited number of spatial object representations like points, lines  Difficult to model other shapes, Needs breakdown of shapes into lines and edges  Scalability  Extensibility  Complexity

 Included in Enterprise Edition of Oracle 10g  Supports 2 schemas  Object Relational  Relational ( Limited support)  Storage, Retrieval, Update, and Querying  Per Geometry Instance  Single row  Single column of type MDSYS.SDO_GEOMETRY  Data for County

Every shape / spatial data type can be designed using this data type SDO_GEOMETRY CREATE TYPE sdo_geometry AS OBJECT ( SDO_GTYPE NUMBER, SDO_SRID NUMBER, SDO_POINT SDO_POINT_TYPE, SDO_ELEM_INFO MDSYS.SDO_ELEM_INFO_ARRAY, SDO_ORDINATES MDSYS.SDO_ORDINATE_ARRAY );

 New age applications require complex data types and complex operations  Spatial Data models are necessary to represent them  Relational systems are inefficient to handle such data models  Object Relational systems have necessary and sufficient features to handle them

 Comments, suggestions welcome  Don’t forget the evaluation