[Qgis-user] [Qgis-community-team] QGIS - dissolve and/or buffer limit issues?

[Anita Graser]

>
> 2016-02-09 16:51 GMT+01:00 Andy Gillett <Andy.Gillett at lqm.co.uk>:
>
>> *Objective*
>>
>> I am trying to Dissolve approx. 500,000 polygons which represent a 250m
>> buffer around many line segments (e.g. electrical cable network or could be
>> a road network). I have 5 buffer distances to create in total. The 500,000
>> polygon shp file is a sub-set (approx. 1/10th) of the entire dataset
>> requiring processing in this way.
>> ​
>>
>>
​In my experience, Difference is much faster than Dissolve. Create a big
polygon around the area containing the buffers. Then run Difference on the
polygon layer and the buffer layer, then run it a second time to get the
desired result.

Best wishes,
Anita​
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