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<p>You are comparing apples and pears. <br>
</p>
<p>From a quick scan at the links you posted, the LineCombiner does
a fundamentally different thing than the "network-walking"
example, it simply "combines" any line connected to any other line
at its end vertex, which is not the same as "network-walking".
This is more like a PostGIS "ST_Collect()" operation, that also
doesn't care about network connectivity.<br>
</p>
<p>By the way, I never see PostgreSQL take full CPU (2x14 core
workstation), even with PostgreSQL configured to allow as many CPU
cores for parallel operations as there are physically. I wish it
did, it would speed up some operations that really need it. The
only way I can get full CPU usage is through a custom build Python
multi-threading framework putting PostgreSQL and PostGIS to work.</p>
<p>Maybe your server is underpowered for the type of work you wish
to do.</p>
<p>Marco<br>
</p>
<div class="moz-cite-prefix">Op 22-4-2022 om 01:19 schreef Shaozhong
SHI:<br>
</div>
<blockquote type="cite"
cite="mid:CA+i5JwZqvs19qX6ZRxAQ_Qyaa691NXMjTQSbQUJJs5NxnstS7Q@mail.gmail.com">
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<div dir="ltr">
<div dir="ltr">Whenever geospatial functions such as
St_intersects or recursive query used, the PostGIS appears
to spawn away to many child queries and just obliterate the
CPU. Nothing finishes.
<div><br>
</div>
<div>That forced me to try out to do the some tasks on the
FME server.</div>
<div><br>
</div>
<div>I tried to use this <a
href="http://blog.cleverelephant.ca/2010/07/network-walking-in-postgis.html"
target="_blank" moz-do-not-send="true">http://blog.cleverelephant.ca/2010/07/<span
class="gmail-il">network</span>-walking-in-postgis.html</a> in
the PostGIS.</div>
<div><br>
</div>
<div>I tried to linecombiner in FME. <a
href="https://www.safe.com/transformers/line-combiner/"
moz-do-not-send="true">LineCombiner | FME (safe.com)</a>.</div>
<div><br>
</div>
<div>With a large data set, the running of processors were
monitored. It was estimated the PostGIS one would take 16
days to complete.</div>
<div><br>
</div>
<div>But, it only took a few minute to do the same thing in
FME.</div>
<div><br>
</div>
<div>This suggests that something is not right with the
PostGIS Server.</div>
<div><br>
</div>
<div>Have anyone got experience with configuration and
improving perfomance of PostGIS Server?</div>
<div><br>
</div>
<div>Regards,</div>
<div><br>
</div>
<div>David</div>
</div>
</div>
</div>
<br>
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