Archive for the FDO Category
Just a quick note asking you to VOTE for the solutions you think are best in the current GeoWorld Geospatial Leadership Awards.
Some interesting entries have been nominated. In particular, FDO and Fusion (both open source applications) are competing alongside other prominent applications in the Innovator Award category.
Full disclosure: My work on earth.nanaimo.ca (built with MapGuide Open Source technology) is nominated for the Public Enterprise category. Please only vote for it if you think it’s the most deserving solution in this category.
-J
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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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The recent FDO 3.3.0 release comes with beta support for MS SQL Server Spatial. Adding this provider to MapGuide 2.0.0 on Windows is as simple as copying a few DLLs and updating the XML provider registry.
You’ll have to take my word for it, but all of the layers here are coming from SQL Server 2008:
There are a couple small gotchas that I ran into.
If your data contains geometry inconsistencies (basically anything that doesn’t match OGC geometry specs) then the February CTP of SQL Server 2008 will cause spatial queries to fail. Apparently Microsoft may be relaxing this validity requirement in future CTPs, but for now if you have “invalid” geometry, you will have to modify it.
You can find these problems with the GEOM.STIsValid() function and fix them manually, or you can get SQL Server to “fix” the problems with a statement like this:
update dbo.YOURTABLE set GEOM = GEOM.MakeValid();
The second issue was a defect in the provider that causes spatial filters to fail if you set the SRID (spatial reference) on your data. This is because with SQL Server 2008 the SRID of the filter geometry has to match that of the database, and the provider is not setting a SRID for the filter geometry.
For now, you can work around this by removing the SRID from your features with a statement like this:
update dbo.NAN_PARCELS set GEOM.STSrid = 0;
Apart from these two minor glitches, the provider is looking good so far. I’m hoping to get a chance to test it further with later releases of SQL Server 2008 and of the provider to see how well it performs.
If you get a chance to try this out and run into any further problems, please enter a good description of the problem into the FDO Trac issue tracker. The more you test now, the more likely it will work in your production environment later!
-J
P.S. Thanks to Orest at Autodesk for helping me work through these initial issues!
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Well, after a couple months of holding back MapGuide 1.2 because of raster stability issues, it is now available for download. Tom has posted details here and here, and there is a detailed listing of all the bugs/enhancements on the release page.
So, what’s new? Lots of stuff. I really like the performance enhancements, especially around MapTips, and the ability to easily define “external” data sources. My favourite improvements are around raster handling though. Frank Warmerdam (with some help from me, Andy and Haris) made the GDAL-based raster provide a lot more stable, and added the ability to use bounding boxes in the raster config file, so that only the files required are polled. There are more details on how to use this new feature on the FDO GDAL Trac Wiki.
On the “unannounced news” front, the FDO project has quietly made a Windows build of the FDO Python bindings avaliable for download. There’s a readme in the fdopython zipfile that tells you how to install it.
http://download.osgeo.org/fdo/3.2.3/fdosdk-3.2.3_win32_release.tar.gz
http://download.osgeo.org/fdo/3.2.3/fdopython-3.2.3_win32_release.zip
This requires the MSCC++ 2005 SP1 redistributable. You can get the x86 version here if you need it.
If you’re coming to the FDO lab at FOSS4G, this is what you’ll be using.
-J
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Today, Haris Kurtagic over at SL-King announced the latest release of his cool fdo2fdo utility.
This application hasn’t got much attention yet, but it sure deserves some. Initially used as a test platform for Haris’ open source King.Oracle FDO provider, it has quickly evolved into a general purpose FDO data transfer and inspection toolkit.
Haris does a much better job of describing the functionality of this tool than I ever could in his flash movie. I really encourage you to have a look, but set your resolution to at least 1280×1024 for best viewing. As you’re watching, keep in mind that there is a command line utility included which can perform all of the common schema-related (ExportSchema, CreateDatastore, ApplySchema, CopyData) tasks. For usage you can just navigate to the isntallation folder and type f2fcmd from the Windows command line.
The demo shows SHP, SDF, and Oracle as datastores, but you can easily add any FDO provider to the application. These include things like MySQL, ArcSDE 9.1, and (read-only) any OGR-supported data format. The utility of this application is simply outstanding.
If you paid attention to the movie (and know where I work) you’ll be able to figure out my personal interest in this tool. It has allowed the City to set up a low cost one-click data synchronization between a remote field application and a corporate database. All this required was the judicial use of the “Filter” option, some saved XML transfer tasks, and pre-defined schemas. One cool feature (that we didn’t use) is that you can apply geometry filters, allowing you to transfer a specific area of interest.
fdo2fdo is currently only available in a windows binary download (with Oracle instant client bundled, which is why it’s so big), but Haris has assured me that after he cleans up the code he will be submitting at least the command line and API code to the FDO SVN repository under an appropriate OSI-approved license. Haris is new to the open source world, but he’s catching on really fast.
I believe that the API and command line tool were coded in standard C++, so I’m hoping that they can be ported to Linux shortly after he uploads them. I’m also hoping that the GUI portion of the application will be uploaded. It’s apparently written in MFC, so there isn’t an easy translation to Linux. However, it could act as a model to help someone else build a Linux-based GUI.
-J
