[mapserver-users] Spatialite and spatial index?

Rahkonen Jukka jukka.rahkonen at mmmtike.fi
Sun Jun 23 10:32:40 PDT 2013


Hi,

GDAL has been supporting Spatialite spatial index since http://trac.osgeo.org/gdal/ticket/4212
Some further work was done in http://trac.osgeo.org/gdal/ticket/4508
I am remembering from my own experience that a query like the one you are using needs GDAL 1.10 but with that version the query should be fast. What GDAL version do you have? I guess that you have already checked that you really have a valid spatial index with CheckSpatialIndex SQL function.
I am also remembering that if a huge Spatialite table is built little by little for example by appending separate shapefiles into one common table then the result may be slow even if there is a valid spatial index because the SQLite data file gets so badly fragmented. Running VACUUM may have a great effect in such case.


-Jukka Rahkonen- 
________________________________________
Sven Geggus wrote:

> Hello,

> I have the following entry in a layer which I would like to convert from psql backend
> to spatialite:

> CONNECTIONTYPE POSTGIS
> CONNECTION "dbname=..."
> DATA "geom from (select geom,id,height from contours where height%200=0) as foo using unique id using srid=900913"

> I tried the following:
> CONNECTIONTYPE OGR
> CONNECTION "/path/to/contours.sqlite"
> DATA "select geometry,OGC_FID,height from contours where height%200=0"

> This does work, but does not seem to use the spation Index and is thus
> unusable in conjunction with a file containing Gigabytes of contour
> lines.

> Any hint?

> Sven

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