[[TOC]]
= Vector library in GRASS 7 =

[http://grass.osgeo.org/programming7/vectorlib.html Vector Library] from Programmer's Manual

See also [source:grass/trunk/doc/vector/TODO 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 [wiki:Grass7/VectorLib/OGRInterface 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 [wiki:Grass7/VectorLib/PostGISEditing 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