[OSM-dev] [API] Suggestion: Baselines
Stefan de Konink
stefan at konink.de
Tue May 26 14:10:27 BST 2009
Chris Browet wrote:
> 2009/5/26 Stefan de Konink <stefan at konink.de <mailto:stefan at konink.de>>
> Chris Browet wrote:
> If you just want to materialise the entire database at a certain
> interval, don't you think this will grow very fast?
> I don't know. A baseline would only consist of a list of all
> objects id with their associated version number at a certain
> point in time, not the actual objects...
> Think of a way X; it consist of n nodes. If you take the this way at
> changeset Y, you would still have to find all nodes positions at
> Sure, but as we'd take a version snapshot of all objects anyway, the X
> way will still be only say 8 bytes for the id and n (don't know the
> definaition for versions, let's assume 4) bytes for the version. That is
> 12 bytes per object * 360.000.000 is ~4.5Gb.
> Assuming daily, one year rotating, online baselines, that makes 1.5 Tb,
> i.e. 2 big disks (with overhead), i.e. 200€.
> Not that expensive IMHO...
Then you want a materialised snapshot right? :) I don't think the edit
database should be poluted by this. But it is an option to do what you want.
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