[Openstreetmap-dev] OSM Schema Design

Immanuel Scholz immanuel.scholz at gmx.de
Sun Jan 22 18:32:16 GMT 2006


Hello,

> I may offer you some help in identification of OMS usage scenarios and
> modeling the associated message data exchanged using abstract data.
> Target would be to get as solid basis to develop XML encoding schemes or
> any other encoding schemes.
>
> It is my current understanding that there is currently only one XML
> schema available, which describes the direction from the service to the
> client.
> While this schema applies to all response messages and does describe
> what is currently transfered, I'd like to focus on the long term needs
> of OMS in order to get the structure right.

Until now, I really don't understand what you are talking about. :-?

There is an XML Schema on the wiki which describes the format of the data
objects when transfered. And there is a REST documentation describing the
different ways of accessing the data.

Currently it is possible to access:
- single node
- list of nodes by id
- single segment
- list of segements by id
- list of objects by range (lat/lon rectangle)
- list of gps points by range


> Especially I'd like to separate the discussion on what is transfered
> ('structure') from the discussion on how it is encoded ('encoding').
> Hopefully protocol background will be useful here.

I think profiling skills will help MUCH more. ;) The ruby server is
surprisingly different from usual performance patterns.


> To spend that effort is only useful, if significant changes to the REST
> PI are needed in the mid term.

Don't know what you mean by that either, but it is the current plan to
test implement a CSV output of the object schema (all XML stuff replaced
with a simple CSV), because the server spent most of the time encoding the
XML.
However, nobody came up yet with an actual CSV structure definition, so if
you want to do that, be welcome.


If you want to profile the ruby server (or doing stress tests in other
ways), I can give you directions on how to set up a test server on your
local machine (if you are running linux).


Ciao, Imi.






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