Open Source Databases and GIS

Flexible Technologies for Flexible People

Open Source Databases What Open Source Databases are there?

MySQL PostgreSQL Berkeley DB mSQL SAP DB InterBase

Berkeley DB Embedded database Widely used in software

Sendmail Netscape

Extremely fast Only usable via language bindings

C, C++, TCL, Python Commercially Supported

Sleepycat Software

MySQL Most widely used OSDB Very fast read access, good for web apps SQL interface, ODBC, JDBC Language bindings

C, C++, Perl, Python, TCL Commercially supported

MySQL AB NuSphere

PostgreSQL Most extensible OSDB Object relational design ACID database SQL interface, ODBC, JDBC Language bindings

C, C++, Perl, Python, TCL Commercially supported

PgSQL Inc Red Hat (as Red Hat Database)

Why Not Oracle? Complexity

OSDBs are relatively simple to install and administer

Overhead OSDBs have a lighter system footprint

Cost OSDBs have no licensing fees

Accessibility OSDBs are not a black box

When to use an OSDB? When it is organizationally appropriate When you are accessing data using

standard APIs When you are building web based

applications When you are building deployable

applications When you control the architecture from

end to end

Spatial Data and RDBMs Spatial Databases

Spatial data and attributes reside together in the database

Complex hybrid queries are possibleselect area(forestpoly) from forestcover,history where forestcover.ageclass > 80 and history.restocking = true and forestcover.fid = history.fid and distance( forestcover.forestpoly, GeometryFromText(’POINT(514234,5019313)’,26910) ) < 500

Very large seamless datasets can be stored Unified data models are possible

Spatial Databases Proprietary software

ArcSDE DB2 Spatial OracleSpatial

Open source software PostGIS / PostgreSQL

PostGIS / PostgreSQL Spatial database functionality in

PostgreSQL OpenGIS “Simple Features for

SQL” (SFSQL) as design guide

PostGIS Objects OpenGIS SFSQL Objects

POINT, LINESTRING, POLYGON, MULTIPOINT, MULTILINESTRING, MULTIPOLYGON, GEOMETRYCOLLECTION

OpenGIS SFSQL Representations AsBinary() Well-Known Binary AsText() Well-Known Text

POINT(-128 45) MULTILINESTRING((-128 45,-128 46),(-130 50,-131 55))

PostGIS Functionality Spatial indexing for all object types

R-Tree on GiST Index Analysis functions

Area() Length() Distance() Transform()

PostGIS Data Access Loading / Dumping

Includes shp2pgsql and pgsql2shp utilities OGR utility allows importing from multiple

formats E00Pg utility allows importing from E00 files

Java Includes JDBC Extension Objects for Geometries

C/C++ Using Well-Known Binary over the PostgreSQL

C/C++ API

PostGIS Data Visualization Internet mapping with Mapserver

PHP/Mapscript and PHP/PgSQL to build interactive web mapping applications

ArcIMS emulator with Mapserver to view PostGIS data within Arc8

Java mapping with GeoTools GeoTools has a beta PostGIS layer

data source

PostGIS in the Real World (1)

City of Boston, USA Online property

analysis internal web application

Identify parcels which are proximate and display results using Mapserver

Queensland, AustraliaDepartment of Natural Resources

Forestry permitting internal web application

Query database by attribute and return map of parcel area with supporting information from database

PostGIS in the Real World (2)

I-Cubed Inc, USA Large automated

image processing system

Uses database to coordinate image processing functions, tracking spatial extents of incoming requests and required imagery and farming work out to client computers.

Intevation Gmbh, Germany

Massive multiplayer online game

Players will have mobile devices (pagers, cell phones) and their position recorded in the database. Extraction and visualization tools will be used to visualize game play.

PostGIS in the Real World (3) Finnish Geodetic

Institute Creating nationwide

distributed GIS network using the GeoServer OpenGIS WFS with PostGIS as the database backend

Refractions Research, Canada

Maintaining the Digital Road Atlas, a richly attributed provincial road network. Geometries are integrated into a complex data model including versioning, network integrity, and multiple views of the data.

In Conclusion Open source databases have the

capabilities to handle real world problems, and are in widespread use

Open source spatial databases (PostGIS) are new, but are already in use around the world

Many GIS database problems can now realistically be addressed with open source technology