Wasn't RFC 86 (http://mapserver.org/development/rfc/ms-rfc-86.html) intended to
solve such problems? Does something like the following work and do the job?
SCALETOKEN
NAME "%geometry%"
VALUES
"0" "the_geom"
"1000" "st_simplify(the_geom, 100)"
"10000" "st_simplify(the_geom, 1000)"
END
END
DATA "the_geom from (select %geometry% as the_geom, prop1 from roads) as foo"
Would be nice to know if that would work...
Regards,
Andreas Eichner
> -----Ursprüngliche Nachricht-----
> Von: [email protected] [mailto:mapserver-users-
> [email protected]] Im Auftrag von thomas bonfort
> Gesendet: Dienstag, 31. Dezember 2013 18:46
> An: Rahkonen Jukka
> Cc: Mapserver-Users ([email protected])
> Betreff: Re: [mapserver-users] Automatic simplification based on
> resolution
>
> Jukka,
> IIRC this has already surfaced a few times on the mailing list or the
> bugtracker. MapServer already simplifies geometries at the pixel
> level
> before sending them to the renderers, and from my testing at the time
> was more efficient at doing so than using st_simplify(), with the
> added bonus that the cellsize (resolution, units per pixel) does not
> need to be factored in the actual SQL query, and that the
> simplification applies to all data backends.
> Doing the simplification inside postgis does however make sense if
> the
> data transfer from db to mapserver is a bottleneck, and/or
> potentially
> if reprojection is involved (as less points would need to be fed into
> proj). If you can come up with hard numbers to show there is a gain
> I'd be interested.
>
> regards,
> thomas
>
>
>
> On 31 December 2013 10:31, Rahkonen Jukka <[email protected]>
> wrote:
> > Hi,
> >
> > Mapnik has such a feature
> http://blog.cartodb.com/post/20163722809/speeding-up-tiles-rendering
> > Andrea Aime is experimenting with it with Geoserver and is reaching
> a 50% speedup.
> > http://osgeo-org.1560.x6.nabble.com/Some-interesting-optmizations-
> from-Jonathan-s-load-test-td5095839.html
> > Can Mapserver do the same?
> >
> > -Jukka Rahkonen-
> > _______________________________________________
> > mapserver-users mailing list
> > [email protected]
> > http://lists.osgeo.org/mailman/listinfo/mapserver-users
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