<div dir="ltr"><div><div><div>I looked at the debug output. This time I did not add a virtual field but only using the expression in the rule based renderer:<br><br>src/core/qgsvectorlayerrenderer.cpp: 94: (QgsVectorLayerRenderer) [3ms] rendering v2:<br> Rule-based renderer:<br>RULE - scale [0,0] - filter - symbol []<br> RULE - scale [0,0] - filter attribute(get_feature('einzelobjekte_einzelobjekt','t_id',flaechenelement_von),'art') = 'unterirdisches_Gebaeude' - symbol FILL SYMBOL (1 layers) color 121,174,87,255<br><br>src/core/qgsmaprenderercustompainterjob.cpp: 100: (start) [0ms] Rendering prepared in (seconds): 0.004<br>src/core/qgsmaprenderercustompainterjob.cpp: 232: (doRender) [0ms] [thread:0x23feda0] Starting to render layer stack.<br>src/core/symbology-ng/qgsrulebasedrendererv2.cpp: 839: (startRender) [0ms] [thread:0x23feda0] zLevel 0 -> 0<br>src/providers/postgres/qgspostgresconn.cpp: 992: (openCursor) [2ms] [thread:0x23feda0] Starting read-only transaction: 90310<br>src/providers/postgres/qgspostgresconn.cpp: 992: (openCursor) [2ms] [thread:0x23feda0] Starting read-only transaction: 90310<br>src/providers/postgres/qgspostgresconn.cpp: 1010: (closeCursor) [9ms] [thread:0x23feda0] Committing read-only transaction<br>src/providers/postgres/qgspostgresconn.cpp: 992: (openCursor) [1ms] [thread:0x23feda0] Starting read-only transaction: 90310<br>src/providers/postgres/qgspostgresconn.cpp: 1010: (closeCursor) [9ms] [thread:0x23feda0] Committing read-only transaction<br>src/providers/postgres/qgspostgresconn.cpp: 992: (openCursor) [1ms] [thread:0x23feda0] Starting read-only transaction: 90310<br>src/providers/postgres/qgspostgresconn.cpp: 1010: (closeCursor) [10ms] [thread:0x23feda0] Committing read-only transaction<br>src/providers/postgres/qgspostgresfeatureiterator.cpp: 242: (fetchFeature) [1ms] [thread:0x23feda0] Finished after 2 features<br>src/providers/postgres/qgspostgresconn.cpp: 1010: (closeCursor) [0ms] [thread:0x23feda0] Committing read-only transaction<br>src/core/qgsmaprenderercustompainterjob.cpp: 261: (doRender) [3ms] [thread:0x23feda0] Done rendering map layers<br>src/core/qgsmaprenderercustompainterjob.cpp: 272: (drawLabeling) [0ms] [thread:0x23feda0] Draw labeling start<br>src/core/qgsvectorlayer.cpp: 320: (drawLabels) [0ms] [thread:0x23feda0] Starting draw of labels: einzelobjekte_flaechenelement20151230200140594<br>src/core/qgsmaprenderercustompainterjob.cpp: 299: (drawLabeling) [0ms] [thread:0x23feda0] Draw labeling took (seconds): 0<br>src/core/qgsmaprenderercustompainterjob.cpp: 266: (doRender) [0ms] [thread:0x23feda0] Rendering completed in (seconds): 0.038<br>src/core/qgsmaprenderercustompainterjob.cpp: 201: (futureFinished) [1ms] QPAINTER futureFinished<br>src/core/qgsmaprendererjob.cpp: 327: (cleanupJobs) [0ms] caching image for einzelobjekte_flaechenelement20151230200140594<br>src/core/qgsmaprenderersequentialjob.cpp: 121: (internalFinished) [0ms] SEQUENTIAL finished<br>src/gui/qgsmapcanvas.cpp: 698: (rendererJobFinished) [0ms] CANVAS finish! 1<br>src/core/qgsmaprenderercustompainterjob.cpp: 41: (~QgsMapRendererCustomPainterJob) [3ms] QPAINTER destruct<br>src/core/qgsmaprenderersequentialjob.cpp: 38: (~QgsMapRendererSequentialJob) [4ms] SEQUENTIAL destruct<br><br></div>For few features visible in the mapcanvas it is fast. But really slows down when zooming out. I checked the "execute expression on server side option". With this enabled I would assume that qgspostgresfeatureiterator.cpp would fetch only 1 feature if there is only 1 feature visible in the mapcanvas (according with the filter/expression)? But it alwas fetches all possible features in the map canvas (two in my case).<br><br></div>regards<br></div>Stefan <br><div><div><div><div><br></div></div></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Dec 30, 2015 at 9:34 PM, Stefan Ziegler <span dir="ltr"><<a href="mailto:stefan.ziegler.de@gmail.com" target="_blank">stefan.ziegler.de@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>Two postgres layers with an index on the fields.<br><br></div>Do I see some debug messages (when compiled with DEBUG)? <br></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Dec 30, 2015 at 9:27 PM, Nyall Dawson <span dir="ltr"><<a href="mailto:nyall.dawson@gmail.com" target="_blank">nyall.dawson@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On 31 December 2015 at 06:18, Stefan Ziegler<br>
<span><<a href="mailto:stefan.ziegler.de@gmail.com" target="_blank">stefan.ziegler.de@gmail.com</a>> wrote:<br>
> Hi Nyall<br>
><br>
> I compared 2.12 with current master. But I don't see an improvement. Opening<br>
> the attribute table takes around 10 seconds for layers with approx. 2000<br>
> features with one virtual field (with the attribute(get_feature())<br>
> expression). Rendering is also really slow when using rule based renderer on<br>
> the virtual field.<br>
<br>
</span>What's the data source for each layer? If it's in a database (eg<br>
postgres), is there a suitable index on the joined field?<br>
<span><font color="#888888"><br>
Nyall<br>
</font></span><div><div><br>
<br>
<br>
><br>
> regards<br>
> Stefan<br>
><br>
> On Wed, Dec 30, 2015 at 7:22 PM, Nyall Dawson <<a href="mailto:nyall.dawson@gmail.com" target="_blank">nyall.dawson@gmail.com</a>><br>
> wrote:<br>
>><br>
>><br>
>> On 31 Dec 2015 2:01 AM, "Stefan Ziegler" <<a href="mailto:stefan.ziegler.de@gmail.com" target="_blank">stefan.ziegler.de@gmail.com</a>><br>
>> wrote:<br>
>> ><br>
>> > Hi<br>
>> ><br>
>> > I add a virtual field to a layer with e.g. following expression<br>
>> ><br>
>> > attribute(get_feature('pnf_pnf','t_id',afrom),'year')<br>
>> ><br>
>> > This works really great. Then I'm using this new virtual field for<br>
>> > filtering the features in the rule based renderer. How does affect this the<br>
>> > rendering performance? It seems that it really slows down rendering even<br>
>> > with layers with only approx 600 features each.<br>
>> ><br>
>> > If so, can the speed improved with e.g. some to develop caching<br>
>> > mechanism?<br>
>><br>
>> Try with the current master version - this should be MUCH faster now. I'd<br>
>> love to hear any feedback of how you find the changes improve (or don't<br>
>> improve!) your situation.<br>
>><br>
>> Nyall<br>
>><br>
>> ><br>
>> > regards<br>
>> > Stefan<br>
>> ><br>
>> > _______________________________________________<br>
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><br>
><br>
</div></div></blockquote></div><br></div>
</div></div></blockquote></div><br></div>