[OSM-dev] changes in coastline are not rendered

Oleksiy Muzalyev oleksiy.muzalyev at bluewin.ch
Thu Feb 11 19:03:18 UTC 2016

On 10/02/16 21:57, Mateusz Konieczny wrote:
> On Tue, 9 Feb 2016 11:21:37 +0100
> Oleksiy Muzalyev <oleksiy.muzalyev at bluewin.ch> wrote:
>> On the other hand, I am in doubt, - perhaps, people invested a lot of
>> time and labor in clicking these hundreds and hundreds of nodes, to
>> make a nice looking map, and I am not sure if I am doing the right
>> thing with the tool SHIFT+Y (Simplify Way). Maybe this excessive
>> number of nodes is negligible for the database and rendering?
> I am not sure is there real benefit from way simplification - except
> extreme cases with distance between nodes that is below 1m.
> Note that it is not reducing size of the main OSM database - as anyway
> all old version are stored forever, so any edit will increase its size.
Certainly, I use Simplify Way only in extreme cases, and only if a 
geometry is not worsened. Even if I use it, I always adjust the geometry 
manually afterwards. Usually these are small lakes, short paths, and 
secondary roads. I never simplify sea or ocean coastlines.

At the last conference in New York I asked a man from UK who works with 
the OSM hardware why at the zoom levels 10, 11, 12 the OSM map is 
rendered only once a month. He replied that the rendering program must 
process enormous amount of data at these zoom levels.

Nowadays a lot of landuse=, natural=, etc. is being added in Ukraine, in 
Russia, Kazakhstan, etc. There are also a lot of landuse and natural in 
the USA which are not mapped yet, the same for Africa. These are very 
large territories, that is why I tried to pay attention to obvious 
over-nodding. The disks capacity and processing power are constantly 
growing, so sooner or later it will not be an issue for sure, the 
question is if they are growing fast enough. However, it seems that this 
my concern could be unfounded.

I assume the old versions are kept in separate tables, and they are not 
used for rendering.


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