[OSM-dev] Planet size reduction ideas

[Corey Burger]

On 8/23/07, spaetz <osm at sspaeth.de> wrote:
> Just grepping the planet takes incredibly long nowadays, you can't do anything with it anymore basically, without loading it into a data base.
>
> I very much look forward to the elimination of segments - and the corresponding planet reduction by 40% :-)
>
> 1) Additionally we could do some easy stuff to further reduce size. Currently we have 13 post-comma digits in the latitude and longitude. This leads to what - 1 micrometer ? - precision. Is that really needed? We could easily switch to 7 post-comma digits and still remain within centimeter precision if I am not mistaken. Shaving 2 times 6 digits of 14mio nodes, saves us 170MB or so.

Having this level of accuracy is likely to lead to people assuming our
data is more accurate than it actually is.

>
> 2) Also using INT timestamps will be a lot shorter than the 20char time stamp we have now (although that would strictly mean a change of meaning of that field) and save us another 10 bytes or so.
>  Do we need the timestamps at all? Are they of interest for anyone, if we could drop them completely, that would save a whole bunch.

Timestamps are very very useful and not having them pretty much throws
out a lot of really useful wiki features, like seeing all edits within
a time, when the object was last touched, etc.

Corey