[Gdal-dev] SDE Implementation

[Yewondwossen Assefa]

  This info maybe of interest to the list.


  Are the capabilities more or less similar between the mapserver 
implemenation and the OGR one ?

Thanks,

Frank Warmerdam wrote:
> Howard,
> 
> I have now have the essentials of the read-only SDE vector driver
> complete.  This includes:
>  o Getting list of layers (tables) from registration info
>  o Support for the attribute field types supported by mapsde.c,
>     including date, and blob.
>  o Support for fast GetFeature() fetching the row by rowid.
>  o Support for fast spatial extents from layerinfo.
>  o Support for relatively fast feature counting using a fetch
>     of only the feature ids.
>  o Support for fast spatial query using spatial constraints on stream.
>  o Support for fast attribute filtering using queryinfo where clause.
>  o Support for reading coordinate system (from layerinfo).
>  o Support for point, line and polygon geometries (2d or 3d).
>  o I avoid fetching the layerinfo unless needed.  Normally just for
>     layers that are actively queried rather than all layers in the
>     datasource.
>  o Configuration logic on unix (similar to MapServer config options).
> 
> Still needed:
>  o Support for multi-point, multi-line and multi-polygon geometries.
>  o Support for esoteric field types (XML, etc).
>  o Logic to pass layers names, shape column, and fid column in the
>     datasource names.
>  o Build support on windows.
>  o Review annotation and "cad' data objects for possible support.
> 
> Testing needed:
>  o With no coordref.
>  o Odd field types (blob, date, etc).
>  o Tables with no geometry?
>  o Tables with multiple geometry columns.
>  o datasources with no registration info (SDE for Coverages).
>  o test with 3D layers.
>  o test with measured layers (measures to be ignored).
> 
> All in all the SDE API is pretty straight forward, and this has
> been a surprisingly pleasant activity.  Of course, in large part
> that is due to your providing a setup server, and providing
> me with good documentation.
> 
> If you are feeling ambitious, feel free to try building and
> testing things a bit.
> 
> Best regards,
> --
> ---------------------------------------+--------------------------------------
> 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    | Geospatial Programmer for Rent
> 
> _______________________________________________
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> Gdal-dev at lists.maptools.org
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> 


-- 
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Assefa Yewondwossen
Software Analyst

Email: assefa at dmsolutions.ca
http://www.dmsolutions.ca/

Phone: (613) 565-5056 (ext 14)
Fax:   (613) 565-0925
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