Vector library in GRASS 7

​Vector Library from Programmer's Manual

See also Radim Blažek's TODO​.

File-based spatial index

Done in r38385 and r39148

Memory consumption

• 3D points: GRASS 7 needs much less memory to build the topology (about 5% of the memory needed in GRASS 6.x).
• Support for Lowmem mode added

Done in r44859, r46901

OGR interface

Capability to read OGR layers directly without linking them via v.external and to write OGR layers directly without need to store data in the native vector format and then exporting data using v.out.ogr.

For more information see Direct OGR read and write access.

Simple test of rendering speed

See r47875

• vector map 'bridges' (points=10938)

d.vect bridges type=point

Native:

real    0m0.400s
user    0m0.388s
sys     0m0.008s

Linked PostGIS layer:

real    0m0.828s
user    0m0.568s
sys     0m0.016s

(before r47875)

real    0m5.850s
user    0m1.860s
sys     0m0.464s

• vector map 'roadsmajor' (lines=355)

d.vect roadsmajor type=line

Native:

real    0m0.103s
user    0m0.092s
sys     0m0.008s

Linked PostGIS layer:

real    0m0.521s
user    0m0.128s
sys     0m0.028s

• vector map 'urbanarea' (areas=666)

d.vect urbanarea type=centroid,area

Native:

real    0m0.540s
user    0m0.520s
sys     0m0.016s

Linked PostGIS layer:

real    0m1.236s
user    0m0.736s
sys     0m0.068s

Direct PostGIS geometry editing

For more information see Direct PostGIS geometry editing.

Vector Category Index

Use a search tree to keep the category index always sorted and for fast insertion/deletion. This change would considerably improve the scalability when editing large vectors or adding or removing features while maintaining topology. Needs testing if a search tree is considerably faster than e.g. insertion sort.

TODO

3D vector data support

TODO

See also:

• ​http://lists.osgeo.org/pipermail/grass-dev/2009-September/046131.html