I have a very large dataset (around 1 Million polygons) and I want to dissolve touching polygons so that I can give them one unique ID to then conduct a surface on surface overlayer after a spatial filter based on the group ID of the dissolved polygons. My problem is that after the Dissolve the remnants part with the line features gets very big and exceeds my memory. Is there another more memory-efficient way to handle this?


What I don't understand is that it reads all my Shapefiles and the Wall-Surfaces (millions) without allocating much in my memory but as soon as it comes to the dissolve part it allocates a lot of memory.