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

[Anders Gunnarsson]

> -----Original Message-----
> From: Anders Gunnarsson [mailto:anders.gunnarsson at appello.com]
> Sent: den 15 april 2014 14:32
> To: Sarah Hoffmann
> Cc: geocoding at openstreetmap.org
> Subject: Re: [Geocoding] Fresh Nominatim different than
> nominatim.openstreetmap.org
> 
> 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.

I think I solved this now, I had to set indexed_status = 2 on the countries. It seems like place_force_update only set it for all places in each country but not on the country itself.

> 
> >
> > [1]
> > https://github.com/twain47/Nominatim/commit/589bad809ef11bd8fe94ffa006
> > e1
> > 255efec72480
> >
> > > > > 2). Differences in importance
> > > >
> > > > Have you installed the wikipedia data, as of
> > > > http://wiki.openstreetmap.org/wiki/Nominatim/Installation#Wikipedi
> > > > a_
> > > > 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=t
> > > > > ao
> > > > > %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
> 

Warm regards,
Anders Gunnarsson