[mapserver-dev] mappostgis.c

[thomas bonfort]

I had a go on the geoserver-vs-mapserver test-data, for the simple
shapefile case.

My quick experimenting with shp2img was that the rendering time for a
single image could pass from around .12s using the supplied mapfile,
to around .05s using a cleaned up mapfile with the unused layers
removed.

Do we have any alternatives on the parser front, as I think it is also
a clear weakpoint we have when compared to geoserver on such simple
maps.

thomas

On Tue, Nov 4, 2008 at 23:36, Paul Ramsey <pramsey at cleverelephant.ca> wrote:
> On Tue, Nov 4, 2008 at 10:54 AM, Steve Lime <Steve.Lime at dnr.state.mn.us> wrote:
>> A good threat, probably long overdue. Do you have any feel for the performance end of things? I
>> recall the Geoserver tests showing GeoServer performing substantially better than MapServer w/regards
>> to PostGIS.
>
> OK, this isn't testing against Geoserver, just against 5.2, and the
> result is, 5.4trunk is maybe 5% slower. Which is not unsurprising,
> since now the geometry is transiting a text encoding on the way. I had
> my fingers crossed that the simpler database handling would speed
> things up, but no go.
>
> In terms of straight-up profiling information:
>
> 25% of cycles are still spent in pj_init, and this is *after* I moved
> the two relevant EPSG codes to the top of the file. Geoserver has
> objects cached.
> 20% of cycles are spent in image compression (gif or png). The
> Geoserver ImageIO might have optimized image compressors (my work with
> IPP impresses on me how much gain is available in this area).
>
> The penalty for parsing the proj4 definitions every time, even for
> layers that aren't being drawn, is certainly high, and of course grows
> the more layers you have.  However, these overheads also exist in the
> shape file chain, so the difference between PostGIS and Shape relative
> to Geoserver remains unexplained.
>
> P.
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