Archive for the OSGeo Category
James’ recent post about the GIS Interchange File reminded me that I’ve been meaning to discuss some recent activity on the SQLite front in both FDO and OGR.
Traian Stanev recently proposed the creation of an SQLite provider for FDO. He was quickly arm-wrestled into supporting something close to OGC’s Simple Features for SQL specification, and working with Frank Warmerdam hammered out a GIS spec for SQLite that would work for both OGR and FDO. The beauty is that it’s a single file and can be read by any of the existing SQLite tools.
Traian completed initial development of the SQLite provider a couple weeks ago and Frank expanded OGR’s SQLite support to understand this common specification (this work is in the GDAL/OGR trunk for inclusion in the 1.6 release). These implementations have different strengths. The FDO provider was written to be blazing fast, features an in-memory spatial index, and writes to the FDO binary format. The OGR driver was written for maximum portability and allows writing WKT and WKB. Both implementations will read all three geometry formats and understand the dimension and projection information stored in the OGC-derived metadata tables.
You can download a totally unofficial build of the FDO provider from my website if you want to try it out with MapGuide 2.0 or maybe even Autodesk Map 3D 2009. I have successfully tested it in MapGuide with WKT, WKB, and FGF data. Adding this provider to MapGuide is easy:
- Drop the three files in the zipfile into your Server/bin/fdo directory
- Edit your main providers.xml file to include the SQLite provider using the included XML snippet
- Restart MapGuide
You will need some data. Testing can be done with SQLite files from the OGR sample data directory, but you will eventually want to use your own. It’s fairly simple to convert SDF and SHP. Open up a command window in your Server/bin/fdo directory and type something like:
SQLiteConverter.exe c:\src.sdf c:\dest.db
When creating a new data connection to this file, the provider only takes one configuration parameter: the full path to the file. If you run into any bugs, please post them on the FDO Trac instance.
OGR users that are tracking the trunk build can also try this out. With some amazement, I recently found that the enhancements to this driver had already been documented… obviously OGR places a premium on timely docs. ogr2ogr allows you to do a similar import operation, probably something like (untested):
ogr2ogr -f "SQLite" -dsco FORMAT=WKB dest.db src.shp
You can use additional ogr2ogr arguments to ensure that destination spatial reference and geometry type are written to the metadata tables.
Interestingly enough, a common SQLite GIS specification has been kicked around for quite some time. Last year it was discussed on the OSGeo Discuss mailing list, and more recently further discussion was held on the PostGIS mailing list and a wiki page was set up to collaborate on this idea. Obviously, there is considerable interest within the community. My personal hope is that this specification helps the idea of SQLite as a GIS data store take off.
One area where it could be improved is some kind of integration with Alessandro Furieri’s SpatiaLite extension for SQLite that allows common RDBMS GIS functionality in a native SQLite interface. Unfortunately, neither Frank nor Traian had the cycles to integrate this extension’s data format into the specification or the code at this point. Maybe we’ll get lucky and Alessandro will decide to somehow support this spec, but if not I hope there will be some convergence in the long run.
I know that there was more that I wanted to say, but it’s getting late and I don’t even have time to cut the extra gunk out of this post. Happy SQLiting!
-J
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I have been happily hosted at pair Networks for about twelve years now. A few days ago, one of the users on their private newsgroups asked if anyone had compiled MapServer there. I had never compiled MapServer before, so I figured that I was incredibly qualified to help 
Normally MapServer appears to be fairly simple to install, but there were a couple annoying complications in my scenario. The first was that pair Networks runs exclusively on FreeBSD. The second was that it is an entirely managed service: no root access allowed, no ability to run ldconfig, no changes to php.ini. The net result was that all of the dependencies had to be compiled in static mode, and that a custom PHP CGI had to be used so that the extension_dir could be overridden.
The notes that I took during installation are available if anyone is interested. These are not guaranteed to be accurate, but are pretty close. If you are on pair Networks and trust me (are you crazy?) you can see if the binaries (5 MB) work for you. They are mostly static, so there shouldn’t be any dependencies other than the standard pair libraries, but you never know until you try…
As long as I had it compiled I felt the need to play around. I grabbed some test data from the awesome OSGeo4W project (which allows Windows users to run a large part of the OSGeo stack without hassles) and put them up on my site:
I did run into some problems that I didn’t take the time to solve. I couldn’t get GEOS to link into MapServer properly, and there were some issues with some of the image formats in GDAL. I’m sure that these could have been overcome in time, but it’s the end of the weekend and I have to get back to real life
-J
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If you’re interested in seeing what the recently released MapGuide Open Source 2.0.0 with DM Solutions Fusion (which in turn uses OpenLayers) looks like, you’re in luck!
We’ve put together an experimental / beta server for us to demonstrate and test new features for MapGuide. For now, it’s showing MGOS 2.0.0 Release, with some minor tweaks to the templates to use 8bit PNGs. Have a look here:
http://mapguidebeta.osgeo.org/
-J
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Today, about 24 people gathered in two offices for a videoconference to kick off the Open Source Geospatial Foundation BC Local Chapter (In-Waiting.. we still have to apply for official recognition by OSGeo)
I was really impressed by the number of people who showed up to help us get started, and by the level of energy. We had attendees from all three levels of government, private industry, and geospatial consultants. The official minutes, goals, and objectives will be posted shortly, but my impression is that we are going to be working on regional advocacy and acting as a local support group for sharing ideas and solutions around open source software and data, and open standards.
Bright shiny future, etc, etc… Come join us
-J
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Just a quick note about the formative OSGeo British Columbia Local Chapter
If you are in BC and interested in the promotion or use of open source geospatial (and I haven’t already hit you with the flood of spam to my frequent hangouts), make sure you get signed up and plan to attend our first meeting on November 15 between 11:00am and 2:00pm. For this first session, we will be meeting simultaneously in Victoria and Vancouver, with videoconferencing connecting the sites. A tentative agenda has been drafted in the wiki, but if you have strong feelings one way or another, speak up on the mailing list.
I am extremely happy with the interest in this organisation from all levels of government (with a strong showing by local government - yay team!), private industry, and consulting agencies. I believe that this shows two things. First, that hosting FOSS4G in your region helps to build an awareness of the capabilities of open source geospatial software, and second, that open source geospatial is now at the level that it merits serious consideration as part of any enterprise geospatial strategy.
Even if you cannot attend the initial meeting, I would strongly encourage you to sign up for the mailing list (or its web-based shadow at Nabble) and spark up a conversation.
-J
