Spatial DatabasesSpatial Databases

DT249/DT211/DT228 Semester 2 Semester 2

2006-72006-7

Pat BrownePat Browne

http://www.comp.dit.ie/pbrowne/Spatial%20Databases%20SDEV4005/Spatial%20Databases%20SDEV4005.htm

Course Web PageCourse Web Page

http://www.comp.dit.ie/pbrowne/Spatial%20Databases%20SDEV4005/Spatial%20Databases%20SDEV4005.htm

Your Interest in Spatial Databases Your Interest in Spatial Databases Jobs in GISJobs in GIS

GovernmentGovernment Most major departments are developing GIS on an ongoing basis: e.g. Most major departments are developing GIS on an ongoing basis: e.g.

the Geological Survey of Ireland (GSI), Environment Protection Agency the Geological Survey of Ireland (GSI), Environment Protection Agency (EPA), Duchas, OPW.(EPA), Duchas, OPW.

Semi-statesSemi-states Many agencies have a big investment in GIS e.g. ESB.Many agencies have a big investment in GIS e.g. ESB.

Local AuthoritiesLocal Authorities County councils run many GIS applications.County councils run many GIS applications.

Private SectorPrivate Sector MAPFLOW, IMGS (Information with location).MAPFLOW, IMGS (Information with location).

Post graduate research: Post graduate research: DIT Digital Media Centre (DMC), DIT Digital Media Centre (DMC), The National Centre for The National Centre for

Geocomputation (Maynooth).Geocomputation (Maynooth). Several DT249 students have found new career opportunities as a Several DT249 students have found new career opportunities as a

direct result of completing a spatial database project.direct result of completing a spatial database project.

Your Interest in Spatial Databases Your Interest in Spatial Databases Technically Interesting Technically Interesting

Spatial databases provided the essential Spatial databases provided the essential logiclogic and and structurestructure for a host interesting and creative applications for a host interesting and creative applications (e.g. emergency services routing, hospital placement, a (e.g. emergency services routing, hospital placement, a game environment). game environment).

The spatial database course brings together many topics The spatial database course brings together many topics that you have already studied (e.g. databases, graphics, that you have already studied (e.g. databases, graphics, objection orientation, web development) and applies objection orientation, web development) and applies them in innovative ways.them in innovative ways.

Spatial databases can answer a range of questions from Spatial databases can answer a range of questions from ““where is the nearest chipper?where is the nearest chipper?” to “” to “is Sellafield killing is Sellafield killing us?us?”.”.

Spatial database work with many other technologies Spatial database work with many other technologies (e.g. Internet ,wireless networks, and GPS.) (e.g. Internet ,wireless networks, and GPS.) Great Great source of ideas for final year projectsource of ideas for final year project..

What is a Spatial Database?What is a Spatial Database?

A spatial database is a database system A spatial database is a database system that is optimized to store, update and that is optimized to store, update and query spatial objects: query spatial objects: Point: Point: a house, a moving cara house, a moving car Line: Line: a road segmenta road segment Polygon: Polygon: a countya county

Why Spatial Databases? Queries to databases are posed in high level declarative Queries to databases are posed in high level declarative

manner (usually using SQL)manner (usually using SQL)

SQL is the “lingua-franca” in the commercial database worldSQL is the “lingua-franca” in the commercial database world

Standard SQL operates on relatively simple data typesStandard SQL operates on relatively simple data types

Spatial SQL (SQL3/OGIS) supports several spatial data Spatial SQL (SQL3/OGIS) supports several spatial data types and operationstypes and operations

Additional spatial data types and operations can be defined Additional spatial data types and operations can be defined in spatial database. (CREATE TYPE statement)in spatial database. (CREATE TYPE statement)

A DBMS is a way of storing information in a manner that A DBMS is a way of storing information in a manner that enforces consistency, enforces consistency, facilitates access, facilitates access, Allows users to relate data from multiple tables togetherAllows users to relate data from multiple tables together

Spatial Databases must integrate Spatial Databases must integrate with other applications and data.with other applications and data.

Map Renderer

Network

Wireless Mobile

Devices

HTML Viewer Java Viewer GIS Desktop

Applications

Custom Applications

Spatial DB

(Internet)

Server Side Applications

Query 1Query 1

““Display all counties that Display all counties that borderborder Kildare”. Kildare”. This query can be implemented using the This query can be implemented using the

following SQL command:following SQL command:select c1.name as select c1.name as name,transform(c1.the_geom,4326) as the_geomname,transform(c1.the_geom,4326) as the_geom

from county c1,county c2from county c1,county c2

wherewhere

touches(c1.the_geom,c2.the_geom)touches(c1.the_geom,c2.the_geom)

andand

c2.name='Kildare';c2.name='Kildare';

Result 1Result 1

Query 2Query 2 “ “Display all regional roads that Display all regional roads that intersectintersect the N7 National Primary the N7 National Primary

Road within the region of Dublin Belgard” This query can be Road within the region of Dublin Belgard” This query can be implemented using the following SQL command:implemented using the following SQL command:

SELECT r.class as name,transform(r.the_geom,4326) AS SELECT r.class as name,transform(r.the_geom,4326) AS the_geomthe_geom

FROM regional_road r,national_primary_road n,county cFROM regional_road r,national_primary_road n,county cWHEREWHEREn.class='N7'n.class='N7'ANDANDn.the_geom && r.the_geomn.the_geom && r.the_geomANDANDintersects(n.the_geom,r.the_geom)intersects(n.the_geom,r.the_geom)AND AND c.name='Dublin Belgard'c.name='Dublin Belgard'ANDANDcontains(c.the_geom,intersection(r.the_geom,n.the_geom));contains(c.the_geom,intersection(r.the_geom,n.the_geom));

Result 2Result 2

Course Overview

This course focuses on the use of database management systems (DBMS) to store spatial information. A spatially enabled DBMS is a central component of a Geographical Information System (GIS). GIS has a major role to play in managing the national physical and informational infrastructure. An understanding of spatially enabled DBMS is vital in implementing any information system where geographic data is required. This course focuses on the role of the DBMS in geographical applications.

Course Description 1

Foundations Fundamental geographic concepts for GIS The world in spatial terms, how natural and man made features can be stored in a DBMS. Qualitative and quantitative location e.g. geo-referencing and coordinate systems. Maps as representation of the world and of information. Geometric and thematic information.

Course Description 2

Algorithms for GIS: Intersection of lines, operations on polygons, network traversal, auto-correlation, statistical operations, searching. We focus on the use of algorithms, not their design. The algorithms are provided as database extensions (e.g. PostGIS) or Java APIs (e.g. Open Map, Geotools, uDig, JUMP)

Course Description 3

Spatial representations: Raster, vector, TIN, quadtrees, R-trees, scan orders, polygon coverage, discrete objects, networks, time, connections and topology, networks, distance and direction, flow and diffusion, spatial hierarchies, boundaries, spatial patterns, attributes of relationships. As with the algorithms these representations are provided by the DBMS and APIs.

Course Description 4

Applications of geospatial data: Transportation networks, natural resources, soil data, oceanography, land cover, geology, climate, terrain modelling, land records, administrative boundary data, demographic studies, decision support and health data.

Course Description 5

Spatial databases Spatial data: definitions, formats, models, queries the relational model, advanced SQL, data modelling techniques, implementing a simple database, post relational database models, object-relational and object-oriented models, spatial data structures, spatial indexing e.g. R-Tree, networking, database issues in GIS. The course will involve practical work on a range of appropriate software e.g. PostgreSQL, PostGIS, GML, Java, ArgoCaseGEO, OPENMAP, uDIG .

Learning Outcomes

On completion of the spatial database module, you will be able to: use a database to store and query spatial data develop applications that use a spatially enabled

DBMS understand and use the OGC simple feature model distinguish and use appropriate database models understand the DBMS extensions and APIs required

by application programs to handle spatial data.

Course Text

The course text is: 

Spatial Databases: With Application to GIS by Philippe Rigaux, Michel Scholl, and Agnès Voisard

Publisher ElsevierGoogle Books

 

Good Reference

Spatial Database Book Projecthttp://www.spatial.cs.umn.edu/Book/