On 10/19/2012 04:02 AM, Alex Barth wrote:
On Oct 8, 2012, at 4:00 PM, Paweł Paprota <ppa...@fastmail.fm>
wrote:
On today's EWG meeting we briefly discussed the "OWL-powered
activity/history tab" Top Ten Task.
I want to loop back to the history tab on openstreetmap.org and the
ability to only show changesets that affect data in a bounding box
that Andy and Pawel brought up in [1].
This specific functionality seems like something we'd want directly
supported in the railsport, no? Or is it so expensive that it has to
be tiered out into its separate application?
[1]
http://lists.openstreetmap.org/pipermail/dev/2012-October/025948.html
I agree with Tom and Roland that this functionality belongs to a
third-party tool - the apidb schema is not really suitable for
implementing this kind of thing.
What I think would be good to build:
1. Database schema geared towards analyzing changes in OSM data - that
is a schema where you can easily fast forward through what was going on
in OSM and get some additional "context" information for each change.
Ideally of course you would be able to "checkout" a given revision of
the whole database for any given point in time but that seems like a
monumental task. Right now OSM data is versioned like CVS - each object
separately, there is no notion of a "database revision" like you get in
SVN or Git (think tree for given commit).
This maybe comes back to the discussion of changesets not being atomic.
Which in itself isn't so bad (other than a misleading name...) but the
really tragic thing about OSM changes right now is that there is no easy
way to sort through atomic changes (single changeset uploads) - they get
no id so I guess you're left with trying to figure it out by
timestamp+userid combination?
2. A simple way to instantiate and populate such database - just as you
do with apidb/PostGIS schemas now using e.g. Osmosis.
So in the first version of such schema+tool it would be possible to get
at least some additional information about elements that are in a
specific change, for example when there is a modification of node X it
would be possible to get ways and relations for that node in that point
in time.
I would gladly get involved in such project since it would allow me to
offload a major portion of my work with "changeset activities" to this
new tool/schema/server/whatever we call it.
I think it could be based on OWL however I'm a bit put off by the C++
part to be honest - I don't think the XML parsing and database
operations part really needs to be in C++ since it is certainly not a
bottleneck. I will try to speak with Matt and find out if he would
accept changing the C++ part into Osmosis plugin (which is something he
mentioned to me I think on IRC but said there were no hooks in Osmosis).
Paweł
_______________________________________________
dev mailing list
dev@openstreetmap.org
http://lists.openstreetmap.org/listinfo/dev
