[gdal-dev] shapefile enhancements

[Jan Heckman]

Hi,

I've used and maintained an offshoot shapefile library (thanks, Frank), and
added bits of functionality when needed. There are two that I think might
be of wider interest.

1) possibility to have shapefiles up to 8 GB (instead of 4 GB in ogr or 2
GB elsewhere);
2) implementing deletes.
ad 1) this requires little more than replacing fseek() by _fseeki64() on a
windows box and using the fact that size indicators are about words rather
than bytes.
The use of this feature is limited to library use; afaik gis programs (at
least arcgis) will not be able to use such an extended shapefile.
Next, portability might be an issue.
ad 2) a quick delete without closing and rewriting the .shp and /or the
.dbf file can obviously be useful. Shapefile as well as dBase III files
offer handles to do this.
Issues:
Arcgis wil not recognize .dbf with records marked for deletion (by starting
a record with an asterix instead of a space character);
the (ogr) dbase driver will equally disregard deleted records.
Result: at the end of the session using the shapefile library, the
shapefile can be handled without a major file-rewrite, but the .dbf needs
to have the deleted records removed 'physically'. Still, this can be done
relatively quickly when closing the file.
Portability might again be an issue.

So,does anyone need these features, and is it useful to start a discussion
how to implement either of these enhancements?

regards,
Jan
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