Hi,
See below.
On 2020-12-10 5:36 p.m., Francesco Pelullo wrote:
Il gio 10 dic 2020, 16:50 Nicolas Cadieux <njacadieux.git...@gmail.com
<mailto:njacadieux.git...@gmail.com>> ha scritto:
Hi,
I also used txt files to load LiDAR points in QGIS because .shp
was not good. This was before .gpkg came along, before I learned
Python or CloudCompare. I am just starting to familiarize myself
with the geopackage format so i am no .gpkg expert but this is
what I would do or ask myself:
How are the files stored? Server, USB stick, hard-drive, SSD?
They are usually stored in a SMB server, accessible via VPN because
this Company has multiple offices. However, due to the really slowly
data access, projects and data are moved in local SSD disk before
access/editing.
Are the files in the same CRS as the project? If not, every thing
may be read in cache and reprojected even before you start...
Yes, projects and data layers are created with same CRS.
What happens when the files are simplified? Try more files and
less layer, try more points in the same files.
This could be easy to do, i will check on next job.
Try a fresh project an open the layers one by one. Is one more
problematic than others?
No, It seems to me that geopackages becames slow after some days.
E.g., if i create a new project and new geopackages, qgis has no
problems to open them in a decent time (one or two minutes). But after
some hours, if i close qgis and restart it with the same project/data,
access becames really slow (15 minutes and more).
This is probably what we need to google for then.
I Found this ???
https://gis.stackexchange.com/questions/338478/reading-geopackage-with-large-feature-classes-is-very-slow
Perhaps you should get on the QGIS dev mailing list and ask why
geopackage get progressively slower.
Cheers!
Enough memory?
Win10, i5, 16GB RAM, SSD 1TB, dual screen.
Disable all plugins.
Ok.
Caching features: in your QGIS options, you can change the amount
of featured that are cashed when you open a lector layer. Try
cashing more feature or much less features (like 1). What
happens? If you have a max of 16000 features per layer, chances
are you are caching everything so everything is being loaded to
memory.
Ok i will try.
File creation: how are the files created? Look at the options in
Gdal if the files are created in QGIS.
https://gdal.orgdrivers/vector/gpkg.html
<https://gdal.orgdrivers/vector/gpkg.html> Try creating the files
with Gdal translate (vector menu) instead of just “export as” or
save as in QGIS, force extra option to force index creation.
They are imported in qgis as CSV (are point geometries with a single
attribute as REAL) and then exported in gpkg format.
In export options, spatial index creation is enabled by default.
Do you have a spatial index build in? In theory .gpkg comes with a
spatial index but perhaps you can rebuild one? Or make sure you
build on from the start when you create the file. (See above).
Sometime i run Vacuum from QGIS db manager. Also sometime i force a
new spatial index creation from layer properties, but with no
appreciable differences.
I remember that when I created a .gpkg in python, and used it in
ArcGis, the file would take a long time to open because it was
reading every point of the file in order just to get the files
extent. Maybe that is going on? I think you can specify the files
extent in the file metadata. (I would need to check my code but I
don’t see my solution here. I normally post them whenI find
them...).
https://gis.stackexchange.com/questions/374408/using-geopandas-generated-gpkg-in-arcmap
<https://gis.stackexchange.com/questions/374408/using-geopandas-generated-gpkg-in-arcmap>
Just a bunch of ideas...
Thank you for your suggestions.
--
Nicolas Cadieux
https://gitlab.com/njacadieux
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