[Geocoding] Fresh Nominatim different than nominatim.openstreetmap.org

[Anders Gunnarsson]

Hi Sarah,

Thanks for the fast response so far!

> -----Original Message-----
> From: Sarah Hoffmann [mailto:lonvia at denofr.de]
> Sent: den 11 april 2014 00:15
> To: Anders Gunnarsson
> Cc: geocoding at openstreetmap.org
> Subject: Re: [Geocoding] Fresh Nominatim different than
> nominatim.openstreetmap.org
> 
> On Thu, Apr 10, 2014 at 11:07:09AM +0000, Anders Gunnarsson wrote:
> > From: Sarah Hoffmann [mailto:lonvia at denofr.de]
> > > On Thu, Apr 10, 2014 at 09:12:32AM +0000, Anders Gunnarsson wrote:
> > > > We have made a few fresh installations of Nominatim lately
> > > > according to the documentation on
> > > > http://wiki.openstreetmap.org/wiki/Nominatim/Installation
> > > >
> > > > Our installations sometimes give different results than the
> > > > official
> > > on nominatim.openstreetmap.org. So far we have seen the following
> > > differences:
> > > >
> > > >
> > > > 1). Hits in Norway and Australia get the country code aq
> > > > (Antarctica)
> > >
> > > That's because people keep annexing Antarctica for their own
> > > countries in OSM, see e.g.
> > > http://www.openstreetmap.org/relation/2978650
> > > Nominatim is rather sensitive to this issue and responds by annexing
> > > those countries for Antarctica.
> > >
> > > I had an emergency patch installed on osm.org to prevent that from
> > > happening but apparently forgot to backport it to the official
> version.
> > > I'll try to get around that as soon as possible, feel free to file a
> > > bug report as a reminder. Unfortunately, you will have to reindex
> > > the entire country once the patch is installed.
> >
> > Ok! Any chance I get a patch so I know more or less what I need to do?
> 
> The change is now pushed[1]. You can simply update to the latest version
> and install the changes with:
> ./utils/setup.php --enable-diff-updates --create-functions --create-
> partition-functions
> 
> You then have to find the place_id of the affected countries. They are
> in the URL of the details page. Then log into your database and run:
> 
> select place_force_update(<place_id>);
> 
> followed by: ./utils/update --index --index-instances 2
> 
> This will take a very long time.

I've tested updating the three countries I've found so far, Norway, Australia and Argentina. I see no change though, addressdetails=1 and the details page give cc aq. The data in placex for each country have correct country code, but incorrect calculated country code.

> 
> [1]
> https://github.com/twain47/Nominatim/commit/589bad809ef11bd8fe94ffa006e1
> 255efec72480
> 
> > > > 2). Differences in importance
> > >
> > > Have you installed the wikipedia data, as of
> > > http://wiki.openstreetmap.org/wiki/Nominatim/Installation#Wikipedia_
> > > rank
> > > ings
> >
> > Wiki data has been downloaded and hopefully applied. A lot of places
> have the exact same numbers, but some places like Zagreb differs a lot.
> >
> > How can I verify that the import of wiki data was successful?
> 
> The table wikipedia_article should be aroung 6GB.

Ok, size seems correct.

> 
> > Is it easy to back trace the calculations for importance, to see what
> the importance data is based on??
> 
> There is an entry in the details page that states which wikipedia page
> has been used. If that entry is missing, then importance is simply based
> on the rank of the object.

I see that Wikipedia Calculated is missing for the example I have (Zagreb), while set where Importance is correc. Maybe the wiki data has changed?

> 
> 
> > > > 3). Places not found using structured address search
> > > >
> > > > Query:
> > > > http://nominatim.openstreetmap.org/search.php?format=json&city=tao
> > > > %20y
> > > > uan%20xian&country=taiwan
> > > >
> > > > 10 places found on nominatim.openstreetmap.org vs 0 on our server.
> > >
> > > Check the data of the results on your server on the details page.
> > > For example for the first result of the query, you should check:
> > >
> > > http://<yourserver>/details.php?osm_type=N&osm_id=60655807
> > >
> > > Is the node a city in Taiwan? Also, check that the search for Taiwan
> > > works.
> >
> > It's not, it's a county. Searching for county works in our setup. This
> search came from an old unit test, which turned out to be somewhat
> incorrect. I'm still puzzled why the result differs. Also result on
> osm.org finds the city the test was looking for.
> 
> Do I understand right? node 60655807 is marked as a county on the
> details page on your server?

No, the search term referred to a "taoyuan county" with osm_id 2770986. Though searching for city=taoyuan county&country=Taiwan get hits on osm.org including 60655807, but not on our server. Maybe nothing worth spending time on.

> 
> Sarah

Thanks 
Anders