[Gdal-dev] ArcSDE Support in GDAL/OGR

[Duarte Carreira]

Frank,

I have briefly tested GDAL to export ArcSDE rasters. It is fast, but the
exported image was always shifted. I couldn't see any reason and for
lack of time I postponed further tests until de next version arrives
with the plug-in included. For now we are using a 2 step approach, which
is not very time effective: 1-export to tiff using ArcSDE command-line;
2-convert to other formats using GDAL when required. This doubles our
export times.

I have been testing ArcSDE vector access with several GIS tools, and
didn't find any that would work well enough. Most don't read ArcSDE
vectors; a few Java based do: uDIG and Jump. uDIG has a better feature
set but is too slow with ArcSDE. Jump is faster but does not have enough
functionality for our use. QGIS is getting very attractive but I
couldn't figure a way to connect to ArcSDE. Our favorite FOSS4G desktop
today is Kosmo that reads Oracle Spatial. So we are studying the option
of storing our vector database in sdo_geom format, which ArcSDE can be
configured to write instead of writing the usual SDE blobs. But this has
been a slow process, there are always lots of catches we keep finding
when going down this interoperability road.

In a perfect world, we would be able to have a few core GIS techs
working with top gun GIS tools, managing the database and publishing
pre-configured layers to other GIS users that could use less expensive
tools - where FOSS4G tools would fit nicely. In a more distant future,
as FOSS4G evolves, who knows where this scenario may end up...

Regards,
Duarte

-----Mensagem original-----
De: Frank Warmerdam [mailto:warmerdam at pobox.com] 
Enviada: quinta-feira, 5 de Julho de 2007 20:30
Para: Duarte Carreira
Cc: gdal-dev at lists.maptools.org
Assunto: Re: [Gdal-dev] ArcSDE Support in GDAL/OGR

Duarte Carreira wrote:
> Why am I interested in having GDAL/OGR reading ArcSDE?
>  - ArcGIS is slow exporting raster mosaics - we use ArcSDE 
> command-line utilities which are veeery fast;
>  - ArcSDE command-line tools only export to TIF format;
>  - I would prefer having GDAL exporting to a plethora of formats and 
> letting the user choose one;
>  - I would prefer to use GDAL instead of ArcSDE command-line tools 
> because I feel I shouldn't have to install ArcSDE binaries on users'
> PCs;

Duarte,

The good news is that the current read-only ArcSDE driver in GDAL should
be sufficient for these "extract to another format" uses.

>  - OGR read access to ArcSDE is important to me IF there are GIS 
> desktop tools that use it to access the data (I'm thinking QGIS or 
> others...), and IF mapservers use it (mapserver, geoserver, ...);

MapServer, and GeoServer (via GeoTools) have non-OGR mechanisms to
access ArcSDE vector data so OGR support isn't strictly needed.  It
should be possible to view SDE sourced data in QGIS using the OGR
driver.

SDE vector data can also be used (read only) in GRASS, OpenEV, and other
OGR desktop software though currently it is often hard to get the driver
built in.  Hopefully the standard win32 builds with SDE as a plugin will
help this to some degree.

By the way, it's nice to hear a strong success story with ArcSDE raster
from the horses mouth.  While I still think files in the file system can
be somewhat faster than doing the same thing in a database through some
middleware, I can definitely see huge data management benefits to having
the raster data taken care of in the database with the assistance of
middleware.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam,
warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGeo,
http://osgeo.org