[GRASSLIST:3397] Shapefile, PostGIS -> OGR

Radim Blazek blazek at itc.it
Wed May 12 11:18:27 EDT 2004

OGR layers can be now directly accessed from GRASS (without import).
A new vector representing a link to OGR layer can be created by 
the new module v.external. 
To link shapefile /gdata/shp/myshape.shp run
v.external dsn=/gdata/shp/ layer=myshape output=myshape

To link PostGIS table mytab in database mydb run
v.external dsn='PG:dbname=mydb' layer=mytab output=mytab

To access PostGIS, you need current CVS version of GDAL.
Not all OGR formats are fully supported, e.g. GML can
be read only on level 1 (without topology).

OGR support will substitute former Shapefile and PostGIS
external formats in GRASS in few weeks.
Modules v.format and v.shape.register/v.shape.unregister 
have been removed and a warning is printed when old vector
in one of those formats is opened. 
It is not any more possible to create new PostGIS vectors, 
warning is printed and native format is used.


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