AW: Re: [Qgis-user] QGIS mapserver performance

[Andreas Neumann]

 hm - strange.

 If it works fast in QGIS, it should work equally fast in QGIS server. 
 There shouldn't be any difference.

 Something to investigate - maybe with Marco.

 Are there any messages in the Apache log files (access log or error 
 log?)

 Andreas

 On Mon, 21 Mar 2011 08:38:49 +0100, Ziegler Stefan wrote:
> Scalix message content
> 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 at lists.osgeo.org
>> > http://lists.osgeo.org/mailman/listinfo/qgis-user
>>
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 Andreas Neumann
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