Kedar GawandePosition PaperITK 478Fall 200610/ 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, boundary polygon );

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 Cwhere C.district.Area() > 500 AND overlap(C, R)C.Name C.district.na

meC.district.Area()

R.Name R.Length()

McLean University 520.6549 Niagara 485.0564

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