2012/4/9 Jaak Laineste (Nutiteq) <[email protected]>: > Kuupäeval 9. aprill 2012 22:31 kirjutas Stefan Keller <[email protected]>: >> 2012/4/9 Tom MacWright <[email protected]>: >>> The GEOS dependency is not a long-term challenge, nor spatialite's licensing >>> - you could write a clean-room implementation of both and they would be >>> much-appreciated. But I don't think anyone _will_ write a clean-room >>> implementation unless there's a good reason to, and thus the chicken-and-egg >>> problem of adoption versus implementation. Standardizing abstract file >>> formats without easily-used implementations is not useful: formats need to >>> prove their usefulness through real-world success, or everyone will >>> implement their own. >> >> To understand you correctly: I only need to implement a >> parser/reader/writer of Spatialite's way to put WKB (and the two >> metadata tables) into the existing sqlite file format. >> OGR and QGIS don't need to change anything. > > Almost. Just Spatialite uses internally own BLOB for geography, not WKB [1].
Ok, own BLOB (depends who defined what "well defined" means in the future :->) > To make bbox based queries in OGR and QGIS faster you would want to > generate index data also. Again - I doubt if this is documented > really. Shapefile situation with indexes is also not so good: some > have added own index for live shapefile usage, as public shapefile > spec does not reveal this. So a bit different cases and solutions for > live data usage and bulk loading/conversion cases. > > [1] http://www.gaia-gis.it/gaia-sins/BLOB-Geometry.html Good point I left out up to here: The index file and format. Before all, I don't consider this as a show stopper since an indexes can always be derived and recreated from the original tables. Of course being able to optinally read/write indexes would be a plus and indeed the OGR (any many other) implementations should avoid being dependent on Spatialite libraries. Frank wrote: > My *ambition* was a well specified schema in Sqlite so that > apps could depend on it for interoperability with or without having > spatiallite available. However the spatialite project didn't seem to > want to get tied down to something stable and I lost interest. > > I still like the idea of sqlite as a geodatabase but I haven't the > fortitude to advocate strongly for how I think it ought to work. I did'nt realize that. What do you think should be the next things to be sorted out? -S. _______________________________________________ Geowanking mailing list [email protected] http://geowanking.org/mailman/listinfo/geowanking_geowanking.org
