[GRASS-user] Maximum number of points for v.what.rast

[Rebecca Bennett]

Hi Moritz,

Thanks for responding. 

>Which backend are you using ? 

Backend is currently dbf (default). Is there a preferred option for speeding up 
this type of query?

>Which process is running during all this time ?

Not sure exactly which process is running. I did --verbose but the chat stopped 
after the "excluding x points outside region" message. Any tips on how to tell 
which point it is sticking at would be gratefully received!

>The module executes each individual update query one at a time. Maybe it  might 
>be more efficient >to group them into a temporary file with the  SQL statements 
>and then run that all at once?

Sounds good but I have no idea how to do this - can you point me in the 
direction of some more info so that I could try this method?

Many thanks,
Rebecca





________________________________
From: Moritz Lennert <mlennert at club.worldonline.be>
To: Rebecca Bennett <rabennett at ymail.com>
Cc: grass list <grass-user at lists.osgeo.org>; grass-dev 
<grass-dev at lists.osgeo.org>
Sent: Mon, 2 May, 2011 10:00:41
Subject: Re: [GRASS-user] Maximum number of points for v.what.rast

On 30/04/11 21:50, Rebecca Bennett wrote:
> hello there,
> 
> Does anyone know the maximum number of points that v.what.rast can handle?
> I have a file of 600,000+ points that fails to run (12hrs 100% CPU and
> nothing) and I wonder, before I start with trial and error, if anyone
> knows the answer?

There is no fixed maximum number of points. My guess would be that the time 
needed really depends on the database backend and whether there is an index on 
the category column.

Which backend are you using ? Which process is running during all this time ?



Moritz
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