[GRASS-user] v.external and region bounding box
peter.zamb at gmail.com
Thu Oct 18 03:10:53 PDT 2012
I have imported the Openstreetmap data of Italy into a
Postgis/Postgres, using imposm.
Below are reported the table size in postgis:
Name | Type | Owner | Size |
osm_buildings | table | osm | 805 MB |
osm_landusages | table | osm | 202 MB |
osm_mainroads | table | osm | 105 MB |
osm_minorroads | table | osm | 447 MB |
osm_motorways | table | osm | 12 MB |
osm_railways | table | osm | 12 MB |
I'm using GRASS7. I connected this layers using:
v.external dsn="PG:dbname=osm" layer=osm_*
Even if my region is pretty small, around 9km x 14km, GRASS it's very
slow to load and show the data into the MapDisplay, It seem like all
the vector features are loaded without take into account the region.
If I open the same layers with QGIS, with almost the same region
dimension it's very fast to load/show the data, probably QGIS load
only the features that are in the bounding box.
How can I say to v.external to load only the geometry features that
are in the region boundingbox?
Should I do this manually, making new tables?
ps: v.external return a Segmentation fault when I try to build the
pseudo-topology for the osm_buildings:
GRASS 7.0.svn (UTM32_WGS84):~ > v.external dsn="PG:dbname=osm"
WARNING: Vector map <osm_buildings> already exists and will be overwritten
Building topology for vector map <osm_buildings at dtm_lidar>...
Using external data format 'PostgreSQL' (feature type 'geometry')
Building pseudo-topology over simple features...
 http://download.geofabrik.de/openstreetmap/europe/italy.osm.pbf ~530 Mb
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