Hi Andi > What exactly do you mean by "rendering straight from postgis"? What > software is rendering straight from Postgis? UMN Mapserver, or what > other renderer? Or your own renderer? No, "straight from postgis" means adding the layer in QGIS from postgis. I save this qgis project and make it available as WMS. Since there is only QGIS (as renderer) involved I thought there would not be a big performance difference. Ok, there is apache who is handling the cgi request but that won't take 4 seconds.
> There are some performance bottlenecks regarding clipping of > larger/more > complex polygons. Marco can tell you more. I don't think it's a clipping issue since it's fast when adding the same layer 'straight from postgis' :) So there must be some additional work when making a detour. regards Stefan > > Andreas > > On 3/20/11 2:44 PM, Ziegler Stefan wrote: > > Hi > > > > I have some questions concerning the performance of qgis > mapserver: Using layers with a small amount of polygons I do > not see a big difference between rendering the same layer > straight from postgis and from local qgis mapserver > installation. For a layer with some 400'000 polygons it takes > approx. 4 seconds from qgis mapserver (even for large scales > with only some polygons to render). But it only takes some > fractions of a second when the layer is rendered straight > from postgis (and growing with smaller scales -> more polyons). > > > > Everything is running on a dual core laptop. So there > should be no big download bottleneck. No special styles are > applied to the layers (just a simple fill and an outline). > Are there some requests in addition to "GetMap"? Or what's > responsible for this big difference? > > > > regards > > Stefan > > > > Mit freundlichem Gruss > > Stefan Ziegler > > Leiter amtliche Vermessung > > > > Amt für Geoinformation > > Rötistrasse 4 > > 4501 Solothurn > > 032 627 75 96 > > _______________________________________________ > > Qgis-user mailing list > > Qgis-user@lists.osgeo.org > > http://lists.osgeo.org/mailman/listinfo/qgis-user > > _______________________________________________ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/qgis-user >
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