<div dir="auto">Mike and list,<div dir="auto"><br></div><div dir="auto">Mike, would you please explain why the surface area would be related to the number of threads?</div><div dir="auto"><br></div><div dir="auto">1000 square miles or ~ 250.000 hectares in my units is big but not huge. We have a 7 million hectare vegetation inventory we're updating now.</div><div dir="auto"><br></div><div dir="auto">Do you have a bunch of small tiles? Are you thinking that 1 tile = 1 thread?</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sat, Jul 30, 2022, 12:46 Mike Stanton <<a href="mailto:mfstanton@geospan.com">mfstanton@geospan.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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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 <<a href="mailto:qgis-user-bounces@lists.osgeo.org" target="_blank" rel="noreferrer">qgis-user-bounces@lists.osgeo.org</a>> <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 <<a href="mailto:gdt@lexort.com" target="_blank" rel="noreferrer">gdt@lexort.com</a>><br>
<b>Cc:</b> qgis-user <<a href="mailto:qgis-user@lists.osgeo.org" target="_blank" rel="noreferrer">qgis-user@lists.osgeo.org</a>><br>
<b>Subject:</b> Re: [Qgis-user] excessive threads?<u></u><u></u></p>
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<p class="MsoNormal">Greg and list<u></u><u></u></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" target="_blank" rel="noreferrer">qgis-user@lists.osgeo.org</a>> wrote:<u></u><u></u></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>
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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.<u></u><u></u></p>
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<p class="MsoNormal">[stuff deleted] <u></u><u></u></p>
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I really don't understand:<br>
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What is qgis using threads for?<br>
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Do others see large (100 or so, vs 10) thread counts?<br>
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Why are there 157 (really, why are there more than about 10-20)?<u></u><u></u></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.<u></u><u></u></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" target="_blank" rel="noreferrer">
https://dba.stackexchange.com/questions/251935/number-of-worker-threads-available-in-postgresql</a><u></u><u></u></p>
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<p class="MsoNormal">About SQLite I have no idea.<u></u><u></u></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?<u></u><u></u></p>
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<p class="MsoNormal">Chris Hermansen · clhermansen "at" gmail "dot" com<br>
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C'est ma façon de parler.<u></u><u></u></p>
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