[OSM-dev] OSM XML declaration, JOSM, Osmosis et al.
wrmo at gmx.net
Wed Sep 21 15:26:59 BST 2011
> Is Overpass so geared for tools that don't care about
> uid/date/version/visible etc?
Actually, yes. Note that these tools include map rendering, routing, location based search and probably every other tool that consumes the data. The data model is: the state of the Planet database (or an excerpt) at a fixed point in time, which makes perfectly sense.
Even keeping a database up to date would be possible without meta data: It suffices to know the timestamp of the patches as a whole, not of every individual element, despite the behaviour of possibly picky tools.
The old XAPI had mainly been suffering from a permanent shortage of hardware ressources. You now get a switch to download data three times faster if you omit data that you discard anyway later - if you render a map, do routing, or a lot of other useful things. This would even lower the burden on the still hardware-constrained Overpass API server. A lot of users encounter that useful but some can't make sense of the error messages somewhere later in the toolchain. I can't and I won't rewrite every tool, but I can happly write in the header whatever the tools expect. I simply asking for a consensus for the things to write in the header.
Discussing the usefulness of the current history model is a different question. As I got never an answer to an earlier post on that topic
(it's [osm-talk], I'm sorry), I assume that history is only a minor concern to most users.
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