[OSM-dev] XAPI problems and available queries

Erik Johansson emj at kth.se
Thu Aug 26 09:43:57 BST 2010


I'll try to answer the questions and maybe someone else can fill in
where I get things wrong.

On Wed, Aug 25, 2010 at 9:17 PM, Khoa Tran <ktran9 at mail.usf.edu> wrote:
> 1) Sometimes, XAPI server responds pretty quick for my query. However, for
> some other time, it's very slow like 5 or 10 minutes to get all the nodes
> (http://www.informationfreeway.org/api/0.6/node[highway=bus_stop][bbox=-82.73803000000001,27.70168,-82.153672,28.252141]
> retrieves approximately 3900 nodes. I know this is a large dataset but the
> xml download file is not that big, under 2MB).

Don't know, sometimes things are slow?

> 2) Since data needs to be updated by osmosis to planetdump before XAPI can
> have the new data, I understand that there's a mismatch between real
> openstreetmap database and xapi data. However, I've read on the wiki page
> that planetdump is updated minutely (??). It seems to me it takes more time
> to update the new data. I had to wait 3,4 hours before my new data/change
> took place in XAPI server.

There have been problems with generating the minutely diffs, since the
db updated to pg8.4. Not sure if this will solve it self in the near
time.


> * Is there anything I can do in my application to stay away from the above
> problems? I don't intend to have my own database to handle the same job of
> XAPI server.
> * Is there a way to access OpenStreetMap Postgresql database to GET data
> only besides using the API? I'd love to use something like XAPI but more
> stable.

Only running your own local server, or maybe  take a look at the
different Openstreetmap tool servers out there. I know Openstreetmap,
Wikimedia, French-OSM and German-OSM have tool servers for
openstreetmap, don't think they are ment for this kind of stuff but
you can ask.


> * The last question seems irrelevant to this thread but I can't find an
> answer myself. If a node is deleted, how to get that node WITHOUT the node
> id (e.g. I'd like to use something like
> this http://www.informationfreeway.org/api/0.6/node[highway=bus_stop][bbox=-82.73803000000001,27.70168,-82.153672,28.252141]
> but with all the deleted nodes]

As far as I know there is no such webservice available, except if
Potlatch have a undelete node function. I can give you a copy of the
full history of that area but it takes about 8hours to generate. :-)

/Erik Johansson emj



More information about the dev mailing list