[GRASSLIST:2976] *.pg modules questions

Izak Thomas Henry Deyzel izak at metsys.weathersa.co.za
Thu Jan 24 01:49:42 EST 2002

Hi all,

Hope someone can give me more insight in *.pg modules.

Firstly - how can I declare relations between tables? Should I setup the
db with its relations in postgreSQL? How will it affect querying with
the *.pg modules? I would like to have daily or 3-hourly meteorological
fields avalailable for querying - eg. may want to display an average
field for the whole year with a query. Can't see how I can accomplish
that on the moment with loose tables hanging around. Am I missing

Secondly - how can I import raster, vector (non-shape files), site data
in pgsql with the GRASS-pgsql interface. Do I need to import it normally
in the database with INSERT statements and then use the interface for
quering? Or can I port the GRASS tree structure dbase directly to pgsql?

Thirdly - if I import .shp files the vector data is duplicated in GRASS
tree structure db. Why is that? Can GRASS work only from pgsql or does
it need its own data structures?

Where can I find some detailed documentation on the workings of the
GRASS-pgsql interface?

I've compiled 5pre3 on RH7.2.

Thank you for your help.


Izak T.H. Deyzel
Senior Meteorologist            
South African Weather Service

Tel: +27 58 303 5571
Call our Weatherline at 082 162
Visit SAWS website at   : http://www.weathersa.co.za
Visit METSYS website at : http://metsys.weathersa.co.za

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