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<p class="MsoNormal">Chris, it really depends on how large your project is. Some of my projects cover 1000 sq miles. Usually I don’t use QGIS directly for that, I break it down to smaller pieces.
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<p class="MsoNormal"><b>From:</b> Qgis-user <qgis-user-bounces@lists.osgeo.org> <b>
On Behalf Of </b>chris hermansen via Qgis-user<br>
<b>Sent:</b> Saturday, July 30, 2022 2:37 PM<br>
<b>To:</b> Greg Troxel <gdt@lexort.com><br>
<b>Cc:</b> qgis-user <qgis-user@lists.osgeo.org><br>
<b>Subject:</b> Re: [Qgis-user] excessive threads?<o:p></o:p></p>
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<p class="MsoNormal">Greg and list<o:p></o:p></p>
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<p class="MsoNormal">On Sat, Jul 30, 2022 at 10:38 AM Greg Troxel via Qgis-user <<a href="mailto:qgis-user@lists.osgeo.org">qgis-user@lists.osgeo.org</a>> wrote:<o:p></o:p></p>
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(I realize excessive is relative. Back when I was young, we didn't have<br>
any threads at all....)<br>
<br>
My desktop is NetBSD 9, I ran out of threads, and found that qgis 3.22.8<br>
was using 157 threads, much more than I expected.<o:p></o:p></p>
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<p class="MsoNormal">[stuff deleted] <o:p></o:p></p>
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I really don't understand:<br>
<br>
What is qgis using threads for?<br>
<br>
Do others see large (100 or so, vs 10) thread counts?<br>
<br>
Why are there 157 (really, why are there more than about 10-20)?<o:p></o:p></p>
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<p class="MsoNormal">Seems kind of surprising to me as well. I get that some applications could benefit by parallel execution, and of course separating rendering from file or other I/O seems reasonable, but 157 is a lot of threads for just reading data and
visualizing it.<o:p></o:p></p>
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<p class="MsoNormal">As far as I know, PostgreSQL doesn't even use threads. See for example this discussion
<a href="https://dba.stackexchange.com/questions/251935/number-of-worker-threads-available-in-postgresql">
https://dba.stackexchange.com/questions/251935/number-of-worker-threads-available-in-postgresql</a><o:p></o:p></p>
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<p class="MsoNormal">About SQLite I have no idea.<o:p></o:p></p>
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<p class="MsoNormal">Does it seem like you have one thread per layer for reading plus one for rendering plus one for user input?<o:p></o:p></p>
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<p class="MsoNormal">Chris Hermansen · clhermansen "at" gmail "dot" com<br>
<br>
C'est ma façon de parler.<o:p></o:p></p>
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