What the Heck Is … PostGIS?

Vol. 3 Issue 3
June 2008

Gloria Gaynor once sang "I Will Survive!" (careful - links in this intro have music attached). We all know the tune ... we've all sung it at the top of our lungs at one point -- don't lie, we know you've done it. Well... some of us have survived a few events these past few months. Not only a heat wave at the beginning of June that stunned us all; a snow storm in the middle of May in Denver; a few canceled planes; being re-routed to Los Angeles from Denver to get back to Philly; and making an emergency landing because of a medical emergency on board. So after "surviving", we're just happy to enjoy a few heavenly days. And thank goodness we've been working on great projects for the Philadelphia Police Department, Committee of 70, and the City of Ashville, among others. We've even helped paint a mural! Welcome to another edition of the Azavea Journal.

Every Azavea project has some kind of database components. Most of Azavea’s early projects used commercial databases such as Microsoft SQL Server, Oracle or Microsoft Access. I am a particular fan of SQL Server. Its low price point is paired with high performance and sophisticated features such as OLAP and data mining.

However, there are some terrific open source alternatives as well. PostgreSQL is one that we have been using increasingly over the past year. PostgreSQL is an advanced relational database engine with support for stored procedures, full-text indexing, sub-queries, replication and (yeah!) geospatial data. The GIS support is provided by a project called PostGIS. The founders and lead maintainers of the project are developers at Refractions Research, a small company based in Victoria, British Columbia. PostGIS extends the core PostgreSQL database engine by adding support for geographic objects, including the ability to execute geographic queries using simple SQL. Put another way, it ‘spatially enables’ the PostgreSQL database.

Example of a PostGIS enabled database.

We have used PostgreSQL and PostGIS on several new projects including The Root and the Election Incidents Tracking and Mapping application we built for the Committee of 70 (previous article), with more waiting in the wings. We’re also pleased to see that with ArcGIS 9.3, ESRI will also be adding support for PostgreSQL in the ArcSDE component of the ArcGIS Server platform.
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By PhillyHistory Augmented Reality Journal 2: Building Data Services | Azavea Labs on April 5, 2011 at 4:26 pm

[...] database to find the assets that are within a specific distance from the viewer. Check out this newsletter article from Robert about PostGIS to learn more. It is possible to add a stored procedure to a non-spatial database to make the [...]