[Gdal-dev] Re: SDE Implementation

[Howard Butler]

>
>Still needed:
>  o Support for multi-point, multi-line and multi-polygon geometries.
>  o Support for esoteric field types (XML, etc).

There might be a nice opportunity for linkage with PAM and SDE's XML 
layer metadata stuff.

>  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.

CAD and annotation types in SDE are essentially blobs, I think.  It 
is up to the client to know how to decipher and use them.

>
>Testing needed:
>  o With no coordref.

I don't think it is possible to load a layer into SDE without a 
defined coordinate system.  SDE needs a coordinate system that sets 
up its 2^32-1 coordinate space (they call this the x/y domain)

>  o Odd field types (blob, date, etc).
>  o Tables with no geometry?

Is the ExecuteSQL() method supported by the OGR SDE driver?  People 
will need to be careful about running SQL commands with the SDE 
driver because the SQL will be passed on directly to the database 
behind the SDE (Informix, Oracle, or MS SQL).  The SQL variants 
aren't exactly the same on all three of these databases.

>o Tables with multiple geometry columns.

I'm not sure if multiple geometry columns are possible in SDE.  I 
know that Arc* clients don't support it, and the layerinfo mechanisms 
would be very broken if there were multiple shape columns.  If you 
really want to make SDE go haywire, point it at an Oracle table with 
Oracle spatial geometries and multiple geometry columns ;)


>  o datasources with no registration info (SDE for Coverages).

Thankfully there aren't too many installations of this out there anymore...

>  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.

Will this make SDE raster support an easy toss in? :)


>If you are feeling ambitious, feel free to try building and
>testing things a bit.

I will take care of setting up the Windows makefiles and building it 
out on Windows early next week.

>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