PostGIS Day 2022: Post GIS Vision

Post GIS Vision

Regina Obe

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What time is it now?

PostGIS = Post(GIS) = Post GIS?

Before PostGIS: Plotters (circa 2000)

It's all about maps

My Map

Their Map

Larry Braman, who sadly past away recently, was one of the guys next door. He would stroll along on his wheel chair picking up maps from the plotter, and took an interest in my maps.

What I didn't know about GIS he taught me and what he didn't know about programming and database management I taught him. Larry was a researcher at heart. His maps involved the projects the department was working on and how it impacted the demographics of the neighborhoods and strategizing the best places to build new projects.

One day Larry came to me with an idea. He wanted to build a web application where he could share the results of his research and maps with others in the department without having to print them out. A larger goal was for people to be able to interact with these maps. At the time he was trying to use ArcIMS and wasn't getting too far with it. So I offered to help him since I did know a little bit about web development.

After some effort, I dismissed ArcIMS because it seemed unduly complicated. In my mind what we needed was something to read these files Larry was creating in MapInfo and display them and respond to clicks and with general standard web-development, we could achieve the rest. How hard can that be?

So my hunt started for such a piece of software.

First Step: MapServer

It was at this point I discovered MapServer, incubated by the University of Minnesota, which could read these Mapinfo files in addition to countless others (such as ESRI shapefiles) and display them. It was the first open source GIS tool I had ever used and it just worked and was intuitive and worked exactly how I dreamed such software should work. The hard part was figuring out how to compile it.

Mapserver was not needy like ArcMIS that needed this and that service to run beyond what a normal webserver would provide. Mapserver just worked and worked with things I was already using. Just throw the binary on a server and with the help of a webserver I already had installed the magic happened. That is the thing I most loved about MapServer (it could work with Apache, IIS, and any web server that supported CGI, which was pretty much all of them). You could do all sorts of magic with an executable and a text file that defines your layers. Mapserver too has grown over the years but the basics are still present today and still can be configured as simply. I still love the single executable mode. The only difference now, is you don't have to compile MapServer yourself to use it, and it supports even more web and GIS standards than it did back then. Packages are readily available.

I joined the Mapserver mailing list to learn from others how to use this software.

PostGIS is born

On the mapserver mailing list a new project called PostGIS was announced, and Mapserver could even read the data coming out of this new thing. It needed to run in a database called, PostgreSQL, I hadn't heard of before. But I was comforted that PostgreSQL had SQL in its name. That meant it was built on something I already understood well. Relational database in basic foundation are all the same because they are all based on the SQL standard and share the same ancestry. The hardest part of PostgreSQL was figuring out how to compile it, which I had already made some directions with in my first venture with Mapserver.

I was elated. PostGIS promised I could hold these blobs of things I didn't understand in a database with my relational data and also relate them. I could script it with the power of SQL. It could help Larry and I share data and concepts.

Can't compute

BUG: PostGIS doesn't like my data

"PostGIS doesn't like my data. Here is my data, what's wrong with it?"

I timidly wrote my first bug report cause I wanted so badly for this to work: It went something like this, "PostGIS doesn't like my data. Here is my data, what's wrong with it?" "it" referring to PostGIS or my data or both. I expected to not hear back, or worse laughed at for my ignorance. Instead, I received a personal Thank you within minutes from Paul Ramsey and a code patch shortly after with some sort of explanation I couldn't remember.

I have known Paul since then. Some things never change. We were born in the same year (1971) and thus our ages remain essentially the same and by extension many of our experiences, at least of IT, are similar. The physical distance between us is still the same. The biggest change is that he now pronouces my name correctly instead of like a British Canadian. We are also closer in spirit.

Route to PostGIS (Allusion)

Route to PostGIS in Practice

Stops

XKCD: Wisdom of the Ancients

Trip to PostGIS revisit

SQL Standards are old and new

OSGeo: Open Source Geospatial Foundation

The beginning of OSGeo

When I started using PostGIS, OSGeo did not exist and neither did QGIS. The Proj library, then called proj.4, was an old piece of software designed for Unix. GRASS and MapServer similarly were projects spawned by the US Government (Military and NASA). Both GRASS and Proj predate the existence of Linux. GRASS dates back to the 1980s, similar to PROJ. Mapserver was the first web-based platform to offer visualization for PostGIS. MapServer also used Proj. GDAL was a toolkit that enabled numerous variety spatial data file formats which MapServer started to use. QGIS founder, Gary Sherman, as one of his impetus for creating QGIS (back then known as QuantumGIS) was to provide a desktop visualization tool for the PostGIS he was already using. GRASS was already a project in existence since 1982 founded by US Army Corps of Engineers. GRASS suffered a near death event but was rebirthed in 1997 from the code of GRASS 4.1 release.

And so these projects realized they complemented each other and each held a piece of a pie. If they joined forces they could build a bigger pie. What we now know as OSGeo. This picture depicts the history of some of the early founding projects. Since then many more have been added some who even compete in the same arena such as Geoserver and Mapserver.

PostGIS also has a sentimental significance to me.

I have always struggled with finding my way and reading maps about physical locations. Every place just looks the same to me. I blame that on forced right-handedness in childhood that I feel scrambled my intuitive sense of physical space.

As a young girl of 10 or so, my favorite devices were my graph paper and my computer I called Vic. I'd write programs on Vic to teach my sister, Vicky (short for Victoria, the birthplace of PostGIS), basic math. One program would randomly pick two numbers and draw the number of sticks that matched each number. If Vicky answered a question right, it would show a rocket launching. To figure out all these trajectories I plotted them out on graph paper and I would make them live on Vic. Space has always represented to me where you put things and not necessarily where they physically are.

When I first started using PostGIS, I recognized it as an old friend in a new form. It reduced the world into terms I was familiar with. A reshaping of space to simplify the understanding of it and ability to put things where you want or need them to be rather than accepting them where they are.

Guiding tenents

The present is controlled by the majority.
The future is shaped by the minority.

Detour to Fossils

Clone a Fossil repository

fossil clone https://www.gaia-gis.it/fossil/libspatialite

Local webserver for your local fossil

fossil ui libspatialite.fossil

Import a git repository

git fast-export --all | fossil import --git C:/fossil/FOSS/qgis.fossil

Fossil: https://fossil-scm.org A distributed source control system that runs everywhere and stores more than code. Managed with a single executable that acts as both a commandline client and a web server.

What makes people choose a FOSS product?

The present is controlled by the majority

Market share: Network inertia
Free lunch and good enough
It is better than the other offerings
Libre - liberating, a tool you can change

What makes people support FOSS

The future is shaped by the minority

Libre - liberating, a tool you can change
It is better than the other offerings
Free lunch and good enough (minus the hardware)
Market share: Network inertia

You see a more promising pattern. The very first supporters including the founder of the software are coming because they find it liberating or the alternatives don't work for them. They tend to be very picky people, at least picky about the subject matter, and would rather have an incomplete solution they can change than a complete solution they feel is flawed. So that is why a little known project named PostGIS picked a little known project PostgreSQL, instead of the dominant open source leader MySQL. For the early arrivals your software might not do all they want it to do, but where there are holes they see opportunity. Something happens as more people come on board to help. The software does what they want and it's free. Even though those later folks may not have any desires to add to it, they'll brag about it thus gaining you organic market share. So because of those picky first adopters, the minority of your group, you now have some market share.

I started using PostGIS because I was mostly immune to the network forces that was holding PostGIS back. I lived in a different bubble so to speak. I did not understand there was a GIS market. I saw both Mapserver and PostGIS as tools to augment existing tools I was using, that being SQL and a web server, and they worked seamlessly with those because they built heavily around standards. The fact they were free let me try them without getting the accounts payable department involved. The fact the mailing lists and my bug report response were so welcoming convinced me this is software I can change.

Post GIS Vision

Created with PostGIS svg function and Martin Davis postgis svg helper functions