[Qgis-user] Faster Intersects

[Dennis Burgess]

That did it!!!  I was unware that GeoPackage’s are SUPER fast and that I could SAVE a CSV as a GeoPackage file. . There is no metho to create indexes though once I do this, but now it runs in about 2 min!  lol


[LTI-Full_175px]
Dennis Burgess

Author of "Learn RouterOS- Second Edition”
Link Technologies, Inc -- Mikrotik & WISP Support Services
Office: 314-735-0270  Website: http://www.linktechs.net<http://www.linktechs.net/>
Create Wireless Coverage’s with www.towercoverage.com
Need MikroTik Cloud Management: https://cloud.linktechs.net

From: Alexandre Neto <senhor.neto at gmail.com>
Sent: Friday, September 9, 2022 12:20 PM
To: Dennis Burgess <dmburgess at linktechs.net>
Cc: Raymond Nijssen <r.nijssen at terglobo.nl>; QGIS User <qgis-user at lists.osgeo.org>
Subject: Re: [Qgis-user] Faster Intersects

Following raymond advice,

Move the CSV to a shapefile or geopackage and run the create spatial index on it.

If you have very complex polygons, use suvdivide to create smaller ones save it in shapefile or geopackage and run create spatial index on it.

https://docs.qgis.org/3.22/en/docs/user_manual/processing_algs/qgis/vectorgeometry.html#subdivide

I would try with a smaller subset of points to test the improvement speed before trying to run on the full dataset again.

Answering your question, yes I am pretty sure postgis is much faster than mssql, and yes I think most recent versions of PostgreSQL PostGIS make use of more than one core.

Good luck

A sexta, 9/09/2022, 17:59, Dennis Burgess via Qgis-user <qgis-user at lists.osgeo.org<mailto:qgis-user at lists.osgeo.org>> escreveu:
In the format, are you talking about the shape or the CSV with 2million lines?



Dennis Burgess

Author of "Learn RouterOS- Second Edition”
Link Technologies, Inc -- Mikrotik & WISP Support Services
Office: 314-735-0270  Website: http://www.linktechs.net
Create Wireless Coverage’s with www.towercoverage.com<http://www.towercoverage.com>
Need MikroTik Cloud Management: https://cloud.linktechs.net

-----Original Message-----
From: Qgis-user <qgis-user-bounces at lists.osgeo.org<mailto:qgis-user-bounces at lists.osgeo.org>> On Behalf Of Raymond Nijssen via Qgis-user
Sent: Friday, September 9, 2022 11:11 AM
To: qgis-user at lists.osgeo.org<mailto:qgis-user at lists.osgeo.org>
Subject: Re: [Qgis-user] Faster Intersects

Some things to check:

* Is your data local?
* Is it in a fast file format? (for example .gpkg or .shp and not .csv or .geojson)
* Does the data have a spatial index?
* Is the geometry very complicated, like a huge multi polygon with thousands of vertices and islands? In that case, split it up in several polygons.

Hope this helps. Anyway, it should not need to take this long.

Raymond



On 09-09-2022 16:28, Dennis Burgess via Qgis-user wrote:
> How can I speed up Intersects?  Right now I have a single geometry
> file, but then have about 2 million points that I need to understand
> what intersects that geometry.  Right now its taking 3 days?
> QGIS-bin.exe is only using 11% CPU.. ☹
>
> Dennis
>
>
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