Il gio 10 dic 2020, 16:50 Nicolas Cadieux <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). 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 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.
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