Re: Qgis/Postgis : Multi Union (25 polygonal layers)

2025-07-11 Thread celati Laurent
Good afternoon, Thanks so much for your message. I succeed in executing a postgis script without error message. It is working. However, i notice a lack of reliability/stabilization. Because when I've rerun the same process several times, i never end up with exactly the same number of features in

Overlay of overlapping polygonal datasets : postgis bug/lack of reliability/stabilization ?

2025-07-11 Thread celati Laurent
Good afternoon, I'm taking the liberty to write a message beacause i feel a bug with postgis. As part of a "Overlay of overlapping polygonal datasets" usecase. >From 28 postgis polygon vectors.I try to node and polygonize to make a flat coverage, and then join back to the parent layers to determi

Re: Qgis/Postgis : Multi Union (25 polygonal layers)

2025-07-11 Thread Martin Davis
The reply on GIS StackExchange was a good one, so reproducing it here for this list: Can you investigate further as to the differences between two identical runs, apart from the number of features? Do you get the same behaviour working on a small subset of the data? Can you see if its "sliver" fea