[OSM-dev] Map rendering code... API or database direct?
richard at systemeD.net
Thu Mar 30 10:54:56 BST 2006
Quoting immanuel.scholz at gmx.de:
> On Thursday 30 March 2006 09:14, nick at hogweed.org wrote:
>> Would like to get some feedback on one point though. Should it interact
>> with the database via the API (as a remote client would do) or direct with
>> the database?
> Depends on how much work you will have in the future ;-). The database schema
> is likely to change as it grows and single-tables containing history and
> actual data cannot be handled anymore. Also it is likely that the tag's
> currently inlined into segment and node table move outside.
> Next is, that you cannot easily deploy freemap without the database, if you
> use it directly.
> I suggest you use the API. :)
FWIW, my suggestion would be:
If your display paradigm (i.e. how you're going to draw roads and other routes
on the screen) closely mirrors the API's structures, then use the API -
no reason not to.
If, however, you consider that the best-looking and most user-friendly maps
would be produced by "insulating" the user from OSM's data structures,
most efficient way to do this would be to access the data directly. You
write a set of SQL queries which closer reflect your end uses than the API's
all-purpose transport mechanism does.
If you do this, obviously, it'd still be better to have the data access
a discrete part of your code, so that you don't have to rewrite your entire
project every time the tables change. But this goes without saying, I'm sure.
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