[OSM-dev] Call to mobile developers: OSM binary file format

Marcus Wolschon Marcus at Wolschon.biz
Fri Aug 8 09:48:47 BST 2008



On Fri, 8 Aug 2008 10:34:54 +0200 (CEST), Stefan de Konink <skinkie at xs4all.nl> wrote:
> A binary XML format would be better to parse for an XML processor. But OSM
> data is pretty structured. The point is that for line transfers a pretty
> efficient format can be choosen that is totally unparsible by embedded
> devices.

Well, if it's binary it's no longer XML. wbXML is a binary encoding of XML
but it is no longer XML and it's parser is no longer an XML-parser.

> Since the subject suggest mobile developers; they might only be interested
> in a derrivative format that even *not* includes some information, and has
> a high focus on routing. Now I was always teached that if something
> focusses on one thing it will need to make compromises.

So, do we agree that the focus is routing and navigation -software?
If so, we could move on to finding out what data we actually need to store
and what we can leave out.
Once we know what we are storing, we can start on the "how" to store, retrieve
search, merge and update it.

> Binary XML is cute if there is an efficient parser. But I presume it would
> work as great as any other database format specification. I wonder if even
> OSM in SQLite will give better line speeds.

You got me confused.
What do database-formats have to do with transfer-formats?
You would never use wbxml for storage on a mobile device (you have to load it
into ram and decode instead of indexing into the file) and databases
not for transfer.

Marcus







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