Moritz wrote: > The largest file I have used is about 125000 areas with a > topo file weighing 42M, so taking your worst estimation, > this would mean around 200MB of spatial index, which is > still largely acceptable for me.
lidar and swath bathymetry data will easily have millions of points, and as time goes on this will only expand. I seem to recall that one of Radim's big disappointments was that the need to handle this technology/ data density only really became apparent just when GRASS's new vector engine was nearing completion. With some earlier notice it could have been designed to scale better. Still, there is much tuning which can be done with the present model to reduce the memory overheads, etc. FWIW the sites type (now vector points) in GRASS 4/5 scales well, just as much as you can fit in the text file. (not sure if fseeks are 64bit- proof there, probably not) the biggest lidar file used that I know about is Doug's 379GB dataset (14.5 billion points). The vector engine couldn't handle that* so r.in.xyz was used. Certainly count on 5 million features with topology and DB table for dataset sizes /today/. * I don't know what limitation there is if imported without topology+ DB table. In future memory, CPU, and HD sizes will only increase, but one thing I've come to respect is that GRASS's raster modules scale so well today because they were designed to function in the days of extremely tight memory and CPU constraints. you might look at libLAS (for lidar data -- an OSGeo semi-affiliated project: http://liblas.org/ It is my understanding that Howard is currently adding spatial index support in the development version. You might check out his approach. I have been, and still am ignorant of what advantage a spatial index gives you for point data. ... interested to learn why "topology" would be useful for points-only data. In general I'm fairly happy with the no-topology solution for lidar data in grass, but a few targeted modules (eg v.info) really need to be modified to deal with them. Hamish ps- we still need to hunt through the archives for Radim's posts on these issues which explain quite a bit. _______________________________________________ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev