Cool, I didn't think to look at the shapefile help for DBF info. Makes sense.
I was able to index the DBF and the join processed in seconds, which was running for hours before without finishing. Sweet. On Apr 25, 2012, at 7:53 PM, Frank Warmerdam wrote: > William, > > Yes, but only in a very restricted fashion. The shapefile driver docs says: > > """Currently the OGR Shapefile driver only supports attribute indexes > for looking up specific values in a unique key column. To create an > attribute index for a column issue an SQL command of the form "CREATE > INDEX ON tablename USING fieldname". To drop the attribute indexes > issue a command of the form "DROP INDEX ON tablename". The attribute > index will accelerate WHERE clause searches of the form "fieldname = > value". The attribute index is actually stored as a mapinfo format > index and is not compatible with any other shapefile applications.""" > > I think that is still accurate. > > Best regards, > Frank > > > > On Wed, Apr 25, 2012 at 5:38 PM, William Kyngesburye > <wokl...@kyngchaos.com> wrote: >> Is it possible to index fields in a DBF, and does GDAL support that for a >> JOIN? >> ----- William Kyngesburye <kyngchaos*at*kyngchaos*dot*com> http://www.kyngchaos.com/ "History is an illusion caused by the passage of time, and time is an illusion caused by the passage of history." - Hitchhiker's Guide to the Galaxy _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
