[mapserver-users] Does Mapserver utilise Spatialite spatial index correctly?

[Even Rouault]

Selon "Lime, Steve D (DNR)" <Steve.Lime at state.mn.us>:

> The changeset in OGR is in the spatialite driver so it doesn't look like a
> program using the OGR APIs would need to do anything special. Someone
> familiar with the OGR driver will have to weigh in I suspect...

Does the OGR backend of MapServer always use OGR_L_SetSpatialFilter() ? I've not
MapServer source code under my eyes right now, but I'm wondering if there's not
a different code path according to if you specify in the mapfile a OGR layer
name or a OGR SQL.

>
> Steve
>
> From: mapserver-users-bounces at lists.osgeo.org
> [mailto:mapserver-users-bounces at lists.osgeo.org] On Behalf Of Rahkonen Jukka
> Sent: Friday, February 10, 2012 9:36 AM
> To: 'mapserver-users at lists.osgeo.org'
> Subject: Re: [mapserver-users] Does Mapserver utilise Spatialite spatial
> index correctly?
>
> Hi,
>
> OK, lets put it this way:
> Is it sure that Mapserver is firing the BBOX query so that GDAL/OGR
> understands to follow the path that is implemented in
> http://trac.osgeo.org/gdal/changeset/23008
> instead of making an inefficient MBRIntersects()  query or some other slow
> query?
>
> I do not believe that a user like me has a possibility to check what really
> happens with Spatialite like I can do with PostGIS and Oracle because
> Spatialite does not collect a log file.
>
> -Jukka Rahkonen-
>
> Lime, Steve D (DNR)  wrote:
> There is no native support for Spatialite in MapServer, it's all through
> GDAL/OGR.
>
> Steve
> ________________________________
> From: mapserver-users-bounces at lists.osgeo.org
> [mapserver-users-bounces at lists.osgeo.org] on behalf of Rahkonen Jukka
> [Jukka.Rahkonen at mmmtike.fi]
> Sent: Friday, February 10, 2012 9:12 AM
> To: 'mapserver-users at lists.osgeo.org'
> Subject: [mapserver-users] Does Mapserver utilise Spatialite spatial index
> correctly?
> Hi,
>
> GDAL was made to utilise Spatialite spatial index effectively if it exists
> with ticket
> http://trac.osgeo.org/gdal/ticket/4212
> After this change ogr2ogr with -spat bounding box query is much faster.
> However, when testing MS4W 3.0.4beta1 which comes with GDAL 1.9, the
> rendering speed of Spatialite data with Mapserver is pretty slow. It is
> evenly slow when zoomed out and zoomed in which makes me believe that the
> spatial index is perhaps not used.
>
> Could it be that Mapserver does not utilise the improved method that was
> implemented for GDAL 1.9 when it is doing spatial queries from Spatialite?
>
> -Jukka Rahkonen-
>