[Gdal-dev] Mapinfo performance - tabfile spatial index
Daniel Morissette
dmorissette at dmsolutions.ca
Thu Jul 22 08:54:14 EDT 2004
Jeremy Palmer wrote:
> Hi,
>
> I'm having problems with the performance of gdal created MapInfo tab files
> from a postgis database. It seems that the tab file does not get spatially
> index upon creation... I used OGR2OGR to extract geometries from a postgis
> database. The source postgis table has a 'geometry' type. The command I used
> to create the table was:
>
> ogr2ogr -f "Mapinfo File" parcel PG:dbname=testgis -sql "SELECT id
> translate(shape, 160,0,0) FROM crs_parcel" -nln parcel -a_srs "EPSG:4167"
>
> My question is: I'm I doing something wrong with the creation of the file,
> or is it just that the MapInfo driver does not support spatial indexing?
>
I don't think you're doing something wrong. The MapInfo TAB driver does
create a spatial index but it is not always properly balanced, that
could explain the poor performance in some cases. Unfortunately there is
not much you can do about this, unless you feel like spending time
understanding and improving the generation of the spatial index in the
code (or are able to fund someone to do it).
Daniel
--
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Daniel Morissette dmorissette at dmsolutions.ca
DM Solutions Group http://www.dmsolutions.ca/
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