[Qgis-user] Intersect Performance

[Bjorn Nyberg]

Hmm maybe i will give PostGIS a try, I am simply mystified why the quickest
GRASS intersect should take ~47min compared to ~3min in ArcGIS. SAGA was
the quickest for me at 15min although that produced the wrong results (did
not intersect all the lines).
Cheers anyways,
Bjorn


On Sun, Sep 22, 2013 at 8:45 PM, G. Allegri <giohappy at gmail.com> wrote:

> Keep in mind that with GRASS you need your data to be topologically quite
> clean, because it treat them topologically.
> QGIS's internal overlay processing isn't very optimized...
>
> Sent from Nexus
> Il giorno 22/set/2013 18:53, "António M. Rodrigues" <
> amcrgrodrigues at gmail.com> ha scritto:
>
> Hi,
>>
>> As expected, GRASS 7 out-performs all the others. Nowdays, when working
>> with large datasets, I rather use PostGIS. Fast, robust. With GRASS 7 you
>> can easily talk to your postgres databases which is a great help.
>>
>> You could try GRASS from QGIS but as far as I know, qgis doens't peak to
>> grass7.
>>
>> Cheers,
>> António
>>
>>
>> 2013/9/18 bjorn.burr.nyberg at gmail.com <bjorn.burr.nyberg at gmail.com>
>>
>>> Any suggestion on this? Reason I ask is that its quite a fundamental
>>> step in
>>> my scripts.
>>>
>>> see
>>>
>>> http://gis.stackexchange.com/questions/71632/grass-v-overlay-qgis-intersect-speed-intersecting-line-and-polygon
>>>
>>> Cheers
>>>
>>>
>>>
>>> --
>>> View this message in context:
>>> http://osgeo-org.1560.x6.nabble.com/Intersect-Performance-tp5077130p5078413.html
>>> Sent from the Quantum GIS - User mailing list archive at Nabble.com.
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>>
>>
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