not add your bugs to closed issues. They may looks similar to you but
often are completely different from the maintainer's point of view.
-### When Reporting Bad Search Results...
-
-Please make sure to add the following information:
-
- * the URL of the query that produces the bad result
- * the result you are getting
- * the expected result, preferably a link to the OSM object you want to find,
- otherwise an address that is as precise as possible
-
-To get the link to the OSM object, you can try the following:
-
- * go to https://openstreetmap.org
- * zoom to the area of the map where you expect the result and
- zoom in as much as possible
- * click on the question mark on the right side of the map,
- then with the queston cursor on the map where your object is located
- * find the object of interest in the list that appears on the left side
- * click on the object and report the URL back that the browser shows
-
-### When Reporting Bugs...
-
-Please add the following information to your issue:
-
- * hardware configuration: RAM size, CPUs, kind and size of disks
- * Operating system (also mention if you are running on a cloud service)
- * Postgres and Postgis version
- * list of settings you changed in your Postgres configuration
- * Nominatim version (release version or,
- if you run from the git repo, the output of `git rev-parse HEAD`)
- * (if applicable) exact command line of the command that was causing the issue
-
-Bug reports that do not include extensive information about your system,
-about the problem and about what you have been trying to debug the problem
-will be closed.
-
## Workflow for Pull Requests
We love to get pull requests from you. We operate the "Fork & Pull" model
@define('CONST_Osm2pgsql_Flatnode_File', '/path/to/flatnode.file');
Replace the second part with a suitable path on your system and make sure
-the directory exists. There should be at least 64GB of free space.
+the directory exists. There should be at least 75GB of free space.
## Downloading additional data
cd $NOMINATIM_SOURCE_DIR/data
wget https://www.nominatim.org/data/wikimedia-importance.sql.gz
-The file is about 400MB and adds around 4GB to Nominatim database.
+The file is about 400MB and adds around 4GB to the Nominatim database.
!!! tip
If you forgot to download the wikipedia rankings, you can also add
wget https://www.nominatim.org/data/gb_postcode_data.sql.gz
wget https://www.nominatim.org/data/us_postcode_data.sql.gz
-## Choosing the Data to Import
+## Choosing the data to import
In its default setup Nominatim is configured to import the full OSM data
set for the entire planet. Such a setup requires a powerful machine with
-at least 64GB of RAM and around 800GB of SSD hard disks. Depending on your
+at least 64GB of RAM and around 900GB of SSD hard disks. Depending on your
use case there are various ways to reduce the amount of data imported. This
section discusses these methods. They can also be combined.
### Using an extract
-If you only need geocoding for a smaller region, then precomputed extracts
+If you only need geocoding for a smaller region, then precomputed OSM extracts
are a good way to reduce the database size and import time.
[Geofabrik](https://download.geofabrik.de) offers extracts for most countries.
They even have daily updates which can be used with the update process described
-below. There are also
+[in the next section](../Update). There are also
[other providers for extracts](https://wiki.openstreetmap.org/wiki/Planet.osm#Downloading).
Please be aware that some extracts are not cut exactly along the country
To give you an idea of the impact of using the different styles, the table
below gives rough estimates of the final database size after import of a
-2018 planet and after using the `--drop` option. It also shows the time
-needed for the import on a machine with 64GB RAM, 4 CPUS and SSDs. Note that
-the given sizes are just an estimate meant for comparison of style requirements.
-Your planet import is likely to be larger as the OSM data grows with time.
+2020 planet and after using the `--drop` option. It also shows the time
+needed for the import on a machine with 64GB RAM, 4 CPUS and NVME disks.
+Note that the given sizes are just an estimate meant for comparison of
+style requirements. Your planet import is likely to be larger as the
+OSM data grows with time.
style | Import time | DB size | after drop
----------|--------------|------------|------------
-admin | 5h | 190 GB | 20 GB
-street | 42h | 400 GB | 180 GB
-address | 59h | 500 GB | 260 GB
-full | 80h | 575 GB | 300 GB
-extratags | 80h | 585 GB | 310 GB
+admin | 4h | 215 GB | 20 GB
+street | 22h | 440 GB | 185 GB
+address | 36h | 545 GB | 260 GB
+full | 54h | 640 GB | 330 GB
+extratags | 54h | 650 GB | 340 GB
-You can also customize the styles further. For a description of the
-style format see [the development section](../develop/Import.md).
+You can also customize the styles further.
+A [description of the style format](../develop/Import.md#configuring-the-import)
+can be found in the development section.
## Initial import of the data
First try the import with a small extract, for example from
[Geofabrik](https://download.geofabrik.de).
-Download the data to import and load the data with the following command
-from the build directory:
+Download the data to import. Then issue the following command
+from the **build directory** to start the import:
```sh
./utils/setup.php --osm-file <data file> --all 2>&1 | tee setup.log
```
-***Note for full planet imports:*** Even on a perfectly configured machine
-the import of a full planet takes at least 2 days. Once you see messages
+### Notes on full planet imports
+
+Even on a perfectly configured machine
+the import of a full planet takes around 2 days. Once you see messages
with `Rank .. ETA` appear, the indexing process has started. This part takes
the most time. There are 30 ranks to process. Rank 26 and 30 are the most complex.
They take each about a third of the total import time. If you have not reached
### Notes on memory usage
-In the first step of the import Nominatim uses osm2pgsql to load the OSM data
-into the PostgreSQL database. This step is very demanding in terms of RAM usage.
-osm2pgsql and PostgreSQL are running in parallel at this point. PostgreSQL
-blocks at least the part of RAM that has been configured with the
-`shared_buffers` parameter during [PostgreSQL tuning](Installation#postgresql-tuning)
+In the first step of the import Nominatim uses [osm2pgsql](https://osm2pgsql.org)
+to load the OSM data into the PostgreSQL database. This step is very demanding
+in terms of RAM usage. osm2pgsql and PostgreSQL are running in parallel at
+this point. PostgreSQL blocks at least the part of RAM that has been configured
+with the `shared_buffers` parameter during
+[PostgreSQL tuning](Installation#postgresql-tuning)
and needs some memory on top of that. osm2pgsql needs at least 2GB of RAM for
its internal data structures, potentially more when it has to process very large
relations. In addition it needs to maintain a cache for node locations. The size
by default, so you do not need to configure anything in this case.
For imports without a flatnode file, set `--osm2pgsql-cache` approximately to
-the size of the OSM pbf file (in MB) you are importing. Make sure you leave
-enough RAM for PostgreSQL and osm2pgsql as mentioned above. If the system starts
-swapping or you are getting out-of-memory errors, reduce the cache size or
-even consider using a flatnode file.
+the size of the OSM pbf file you are importing. The size needs to be given in
+MB. Make sure you leave enough RAM for PostgreSQL and osm2pgsql as mentioned
+above. If the system starts swapping or you are getting out-of-memory errors,
+reduce the cache size or even consider using a flatnode file.
### Verify the import
### Setting up the website
-Run the following command to set up the configuration file for the website
+Run the following command to set up the configuration file for the API frontend
`settings/settings-frontend.php`. These settings are used in website/*.php files.
```sh
planet import 64GB of RAM or more are strongly recommended. Do not report
out of memory problems if you have less than 64GB RAM.
-For a full planet install you will need at least 800GB of hard disk space
-(take into account that the OSM database is growing fast). SSD disks
-will help considerably to speed up import and queries.
+For a full planet install you will need at least 900GB of hard disk space.
+Take into account that the OSM database is growing fast.
+Fast disks are essential. Using NVME disks is recommended.
Even on a well configured machine the import of a full planet takes
-at least 2 days. Without SSDs 7-8 days are more realistic.
+around 2 days. On traditional spinning disks, 7-8 days are more realistic.
## Tuning the PostgreSQL database
git clone https://github.com/osm-search/nominatim-ui
-Adapt the configuration `dist/config.js` to your needs. You need at least
+Copy the example configuration into the right place:
+
+ cd nominatim-ui
+ cp dist/config.example.js dist/config.js
+
+Now adapt the configuration to your needs. You need at least
to change the `Nominatim_API_Endpoint` to point to your Nominatim installation.
Then you can just test it locally by spinning up a webserver in the `dist`
~(^|&)format= other;
}
-# Determine from the URI and the format parameter aboce if forwarding is needed.
+# Determine from the URI and the format parameter above if forwarding is needed.
map $uri/$format $forward_to_ui {
default 1; # The default is to forward.
~^/ui 0; # If the URI point to the UI already, we are done.
The following section describes how to keep it up-to-date with Pyosmium.
For a list of other methods see the output of `./utils/update.php --help`.
-!!! warning
+!!! important
If you have configured a flatnode file for the import, then you
- need to keep this flatnode file around for updates as well.
+ need to keep this flatnode file around for updates.
#### Installing the newest version of Pyosmium
# Place details
-Lookup details about a single place by id. The default output is HTML for debugging search logic and results.
+Show all details about a single place saved in the database.
-**The details page (including JSON output) exists for debugging only and must not be downloaded automatically**, see [Nominatim Usage Policy](https://operations.osmfoundation.org/policies/nominatim/).
+!!! warning
+ The details page exists for debugging only. You may not use it in scripts
+ or to automatically query details about a result.
+ See [Nominatim Usage Policy](https://operations.osmfoundation.org/policies/nominatim/).
## Parameters
The details API supports the following two request formats:
-```
- https://nominatim.openstreetmap.org/details?osmtype=[N|W|R]&osmid=<value>&class=<value>
+``` xml
+https://nominatim.openstreetmap.org/details?osmtype=[N|W|R]&osmid=<value>&class=<value>
```
-`osmtype` and `osmid` are required parameter. The type is one of node (N), way (W)
+`osmtype` and `osmid` are required parameters. The type is one of node (N), way (W)
or relation (R). The id must be a number. The `class` parameter is optional and
allows to distinguish between entries, when the corresponding OSM object has more
than one main tag. For example, when a place is tagged with `tourism=hotel` and
but the `class` parameter is left out, then one of the places will be chosen
at random and displayed.
-```
- https://nominatim.openstreetmap.org/details?place_id=<value>
+``` xml
+https://nominatim.openstreetmap.org/details?place_id=<value>
```
-Placeids are assigned sequentially during Nominatim data import. The id for a place is different between Nominatim installation (servers) and changes when data gets reimported. Therefore it can't be used as permanent id and shouldn't be used in bug reports.
+Place IDs are assigned sequentially during Nominatim data import. The ID
+for a place is different between Nominatim installation (servers) and
+changes when data gets reimported. Therefore it cannot be used as
+a permanent id and shouldn't be used in bug reports.
Additional optional parameters are explained below.
### Output format
-* `format=[html|json]`
-
-See [Place Output Formats](Output.md) for details on each format. (Default: html)
-
* `json_callback=<string>`
Wrap JSON output in a callback function (JSONP) i.e. `<string>(<json>)`.
-Only has an effect for JSON output formats.
* `pretty=[0|1]`
-For JSON output will add indentation to make it more human-readable. (Default: 0)
+Add indentation to make it more human-readable. (Default: 0)
### Output details
* `addressdetails=[0|1]`
-Include a breakdown of the address into elements. (Default for JSON: 0, for HTML: 1)
+Include a breakdown of the address into elements. (Default: 0)
* `keywords=[0|1]`
* `linkedplaces=[0|1]`
-Include details of places higher in the address hierarchy. E.g. for a street this is usually the city, state, postal code, country. (Default: 1)
+Include a details of places that are linked with this one. Places get linked
+together when they are different forms of the same physical object. Nominatim
+links two kinds of objects together: place nodes get linked with the
+corresponding administrative boundaries. Waterway relations get linked together with their
+members.
+(Default: 1)
* `hierarchy=[0|1]`
-Include details of places lower in the address hierarchy. E.g. for a city this usually a list of streets, suburbs, rivers. (Default for JSON: 0, for HTML: 1)
+Include details of places lower in the address hierarchy. (Default: 0)
* `group_hierarchy=[0|1]`
* `polygon_geojson=[0|1]`
-Include geometry of result. (Default for JSON: 0, for HTML: 1)
+Include geometry of result. (Default: 0)
### Language of results
## Examples
-##### HTML
-
-[https://nominatim.openstreetmap.org/details.php?osmtype=W&osmid=38210407](https://nominatim.openstreetmap.org/details.php?osmtype=W&osmid=38210407)
-
##### JSON
[https://nominatim.openstreetmap.org/details.php?osmtype=W&osmid=38210407&format=json](https://nominatim.openstreetmap.org/details.php?osmtype=W&osmid=38210407&format=json)
Either use a standard RFC2616 accept-language string or a simple
comma-separated list of language codes.
+### Polygon output
+
+* `polygon_geojson=1`
+* `polygon_kml=1`
+* `polygon_svg=1`
+* `polygon_text=1`
+
+Output geometry of results as a GeoJSON, KML, SVG or WKT. Only one of these
+options can be used at a time. (Default: 0)
+
+* `polygon_threshold=0.0`
+
+Return a simplified version of the output geometry. The parameter is the
+tolerance in degrees with which the geometry may differ from the original
+geometry. Topology is preserved in the result. (Default: 0.0)
### Other
The [/reverse](Reverse.md), [/search](Search.md) and [/lookup](Lookup.md)
API calls produce very similar output which is explained in this section.
-There is one section for each format which is selectable via the `format`
-parameter.
+There is one section for each format. The format correspond to what was
+selected via the `format` parameter.
-## Formats
-
-### JSON
+## JSON
The JSON format returns an array of places (for search and lookup) or
a single place (for reverse) of the following format:
"wikipedia": "en:London",
"population": "8416535"
}
- },
+ }
```
The possible fields are:
* `place_id` - reference to the Nominatim internal database ID ([see notes](#place_id-is-not-a-persistent-id))
- * `osm_type`, `osm_id` - reference to the OSM object
+ * `osm_type`, `osm_id` - reference to the OSM object ([see notes](#osm-reference))
* `boundingbox` - area of corner coordinates ([see notes](#boundingbox))
* `lat`, `lon` - latitude and longitude of the centroid of the object
* `display_name` - full comma-separated address
* `geojson`, `svg`, `geotext`, `geokml` - full geometry
(only with the appropriate `polygon_*` parameter)
-### JSONv2
+## JSONv2
This is the same as the JSON format with two changes:
* `class` renamed to `category`
* additional field `place_rank` with the search rank of the object
-### GeoJSON
+## GeoJSON
This format follows the [RFC7946](https://geojson.org). Every feature includes
a bounding box (`bbox`).
-The feature list has the following fields:
+The properties object has the following fields:
* `place_id` - reference to the Nominatim internal database ID ([see notes](#place_id-is-not-a-persistent-id))
- * `osm_type`, `osm_id` - reference to the OSM object
+ * `osm_type`, `osm_id` - reference to the OSM object ([see notes](#osm-reference))
* `category`, `type` - key and value of the main OSM tag
* `display_name` - full comma-separated address
* `place_rank` - class search rank
Use `polygon_geojson` to output the full geometry of the object instead
of the centroid.
-### GeocodeJSON
+## GeocodeJSON
The GeocodeJSON format follows the
[GeocodeJSON spec 0.1.0](https://github.com/geocoders/geocodejson-spec).
The following feature attributes are implemented:
- * `osm_type`, `osm_id` - reference to the OSM object (unofficial extension)
+ * `osm_type`, `osm_id` - reference to the OSM object (unofficial extension, [see notes](#osm-reference))
* `type` - value of the main tag of the object (e.g. residential, restaurant, ...)
* `label` - full comma-separated address
* `name` - localised name of the place
Use `polygon_geojson` to output the full geometry of the object instead
of the centroid.
-### XML
+## XML
The XML response returns one or more place objects in slightly different
formats depending on the API call.
-#### Reverse
+### Reverse
```
<reversegeocode timestamp="Sat, 11 Aug 18 11:53:21 +0000"
attribution="Data © OpenStreetMap contributors, ODbL 1.0. https://www.openstreetmap.org/copyright"
querystring="lat=48.400381&lon=11.745876&zoom=5&format=xml">
- <result place_id="179509537" osm_type="relation" osm_id="2145268" ref="BY"
+ <result place_id="179509537" osm_type="relation" osm_id="2145268" ref="BY" place_rank="15" address_rank="15"
lat="48.9467562" lon="11.4038717"
boundingbox="47.2701114,50.5647142,8.9763497,13.8396373">
Bavaria, Germany
The place information can be found in the `result` element. The attributes of that element contain:
* `place_id` - reference to the Nominatim internal database ID ([see notes](#place_id-is-not-a-persistent-id))
- * `osm_type`, `osm_id` - reference to the OSM object
+ * `osm_type`, `osm_id` - reference to the OSM object ([see notes](#osm-reference))
* `ref` - content of `ref` tag if it exists
* `lat`, `lon` - latitude and longitude of the centroid of the object
* `boundingbox` - comma-separated list of corner coordinates ([see notes](#boundingbox))
Additional information requested with `addressdetails=1`, `extratags=1` and
`namedetails=1` can be found in extra elements.
-#### Search and Lookup
+### Search and Lookup
```
<searchresults timestamp="Sat, 11 Aug 18 11:55:35 +0000"
attribution="Data © OpenStreetMap contributors, ODbL 1.0. https://www.openstreetmap.org/copyright"
querystring="london" polygon="false" exclude_place_ids="100149"
more_url="https://nominatim.openstreetmap.org/search.php?q=london&addressdetails=1&extratags=1&exclude_place_ids=100149&format=xml&accept-language=en-US%2Cen%3Bq%3D0.7%2Cde%3Bq%3D0.3">
- <place place_id="100149" osm_type="node" osm_id="107775" place_rank="15"
+ <place place_id="100149" osm_type="node" osm_id="107775" place_rank="15" address_rank="15"
boundingbox="51.3473219,51.6673219,-0.2876474,0.0323526" lat="51.5073219" lon="-0.1276474"
display_name="London, Greater London, England, SW1A 2DU, United Kingdom"
class="place" type="city" importance="0.9654895765402"
be more than one. The attributes of that element contain:
* `place_id` - reference to the Nominatim internal database ID ([see notes](#place_id-is-not-a-persistent-id))
- * `osm_type`, `osm_id` - reference to the OSM object
+ * `osm_type`, `osm_id` - reference to the OSM object ([see notes](#osm-reference))
* `ref` - content of `ref` tag if it exists
* `lat`, `lon` - latitude and longitude of the centroid of the object
* `boundingbox` - comma-separated list of corner coordinates ([see notes](#boundingbox))
- * `place_rank` - class search rank
+ * `place_rank` - class [search rank](../develop/Ranking#search-rank)
+ * `address_rank` - place [address rank](../develop/Ranking#address-rank)
* `display_name` - full comma-separated address
* `class`, `type` - key and value of the main OSM tag
* `importance` - computed importance rank
as subelements with the type of the address part.
Additional information requested with `extratags=1` and `namedetails=1` can
-be found in extra elements as sub-element of each place.
+be found in extra elements as sub-element of `extratags` and `namedetails`
+respectively.
## Notes on field values
### place_id is not a persistent id
-The `place_id` is created when a Nominatim database gets installed. A
-single place will have a different value on another server or even when
-the same data gets re-imported. It's thus not useful to treat it as
-permanent for later use.
+The `place_id` is an internal identifier that is assigned data is imported
+into a Nominatim database. The same OSM object will have a different value
+on another server. It may even change its ID on the same server when it is
+removed and reimported while updating the database with fresh OSM data.
+It is thus not useful to treat it as permanent for later use.
The combination `osm_type`+`osm_id` is slighly better but remember in
OpenStreetMap mappers can delete, split, recreate places (and those
e.g. when a restaurant is retagged as supermarket. For a more in-depth
discussion see [Permanent ID](https://wiki.openstreetmap.org/wiki/Permanent_ID).
-Nominatim merges some places (e.g. center node of a city with the boundary
-relation) so `osm_type`+`osm_id`+`class_name` would be more unique.
+If you need an ID that is consistent over multiple installations of Nominatim,
+then you should use the combination of `osm_type`+`osm_id`+`class`.
+
+### OSM reference
+
+Nominatim may sometimes return special objects that do not correspond directly
+to an object in OpenStreetMap. These are:
+
+* **Postcodes**. Nominatim returns an postcode point created from all mapped
+ postcodes of the same name. The class and type of these object is `place=postcdode`.
+ No `osm_type` and `osm_id` are included in the result.
+* **Housenumber interpolations**. Nominatim returns a single interpolated
+ housenumber from the interpolation way. The class and type are `place=house`
+ and `osm_type` and `osm_id` correspond to the interpolation way in OSM.
+* **TIGER housenumber.** Nominatim returns a single interpolated housenumber
+ from the TIGER data. The class and type are `place=house`
+ and `osm_type` and `osm_id` correspond to the street mentioned in the result.
+
+Please note that the `osm_type` and `osm_id` returned may be changed in the
+future. You should not expect to only find `node`, `way` and `relation` for
+the type.
### boundingbox
Comma separated list of min latitude, max latitude, min longitude, max longitude.
The whole planet would be `-90,90,-180,180`.
-Can we used to pan and center the map on the result, for example with leafletjs
+Can be used to pan and center the map on the result, for example with leafletjs
mapping library
`map.fitBounds([[bbox[0],bbox[2]],[bbox[1],bbox[3]]], {padding: [20, 20], maxzoom: 16});`
Bounds crossing the antimeridian have a min latitude -180 and max latitude 180,
-essentially covering the planet (See [issue 184](https://github.com/openstreetmap/Nominatim/issues/184)).
+essentially covering the entire planet
+(see [issue 184](https://github.com/openstreetmap/Nominatim/issues/184)).
### addressdetails
# Reverse Geocoding
-Reverse geocoding generates an address from a latitude and longitude or from
-an OSM object.
+Reverse geocoding generates an address from a latitude and longitude.
+
+## How it works
+
+The reveser geocoding API does not exactly compute the address for the
+coordinate it receives. It works by finding the closest suitable OSM object
+and returning its address information. This may occasionally lead to
+unexpected results.
+
+First of all, Nominatim only includes OSM objects in
+its index that are suitable for searching. Small, unnamed paths for example
+are missing from the database and can therefore not be used for reverse
+geocoding either.
+
+The other issue to be aware of is that the closest OSM object may not always
+have a similar enough address to the coordinate you were requesting. For
+example, in dense city areas it may belong to a completely different street.
+
## Parameters
The main format of the reverse API is
```
-https://nominatim.openstreetmap.org/reverse?<query>
+https://nominatim.openstreetmap.org/reverse?lat=<value>&lon=<value>&<params>
```
-There are two ways how the requested location can be specified:
-
-* `lat=<value>` `lon=<value>`
-
- A geographic location to generate an address for. The coordiantes must be
- in WGS84 format.
-
-* `osm_type=[N|W|R]` `osm_id=<value>`
+where `lat` and `lon` are latitude and longitutde of a coordinare in WGS84
+projection. The API returns exactly one result or an error when the coordinate
+is in an area with no OSM data coverage.
- A specific OSM node(N), way(W) or relation(R) to return an address for.
+Additional paramters are accepted as listed below.
-In both cases exactly one object is returned. The two input parameters cannot
-be used at the same time. Both accept the additional optional parameters listed
-below.
+!!! warning "Deprecation warning"
+ The reverse API used to allow address lookup for a single OSM object by
+ its OSM id. This use is now deprecated. Use the [Address Lookup API](../Lookup)
+ instead.
### Output format
* `format=[xml|json|jsonv2|geojson|geocodejson]`
-See [Place Output Formats](Output.md) for details on each format. (Default: html)
+See [Place Output Formats](Output.md) for details on each format. (Default: xml)
* `json_callback=<string>`
* `zoom=[0-18]`
-Level of detail required for the address. Default: 18. This is a number that corresponds
-roughly to the zoom level used in map frameworks like Leaflet.js, Openlayers etc.
+Level of detail required for the address. Default: 18. This is a number that
+corresponds roughly to the zoom level used in XYZ tile sources in frameworks
+like Leaflet.js, Openlayers etc.
In terms of address details the zoom levels are as follows:
zoom | address detail
* `polygon_threshold=0.0`
-Simplify the output geometry before returning. The parameter is the
+Return a simplified version of the output geometry. The parameter is the
tolerance in degrees with which the geometry may differ from the original
geometry. Topology is preserved in the result. (Default: 0.0)
# Search queries
-The search API allows you to look up a location from a textual description.
-Nominatim supports structured as well as free-form search queries.
+The search API allows you to look up a location from a textual description
+or address. Nominatim supports structured and free-form search queries.
The search query may also contain
[special phrases](https://wiki.openstreetmap.org/wiki/Nominatim/Special_Phrases)
which are translated into specific OpenStreetMap (OSM) tags (e.g. Pub => `amenity=pub`).
-Note that this only limits the items to be found, it's not suited to return complete
-lists of OSM objects of a specific type. For those use [Overpass API](https://overpass-api.de/).
+This can be used to narrow down the kind of objects to be returned.
-## Parameters
-
-The search API has the following two formats:
+!!! warning
+ Special phrases are not suitable to query all objects of a certain type in an
+ area. Nominatim will always just return a collection of the best matches. To
+ download OSM data by object type, use the [Overpass API](https://overpass-api.de/).
-```
- https://nominatim.openstreetmap.org/search/<query>?<params>
-```
+## Parameters
-This format only accepts a free-form query string where the
-parts of the query are separated by slashes.
+The search API has the following format:
```
https://nominatim.openstreetmap.org/search?<params>
```
-In this form, the query may be given through two different sets of parameters:
+The search term may be specified with two different sets of parameters:
* `q=<query>`
Structured requests are faster but are less robust against alternative
OSM tagging schemas. **Do not combine with** `q=<query>` **parameter**.
-All three query forms accept the additional parameters listed below.
+Both query forms accept the additional parameters listed below.
### Output format
-* `format=[html|xml|json|jsonv2|geojson|geocodejson]`
+* `format=[xml|json|jsonv2|geojson|geocodejson]`
-See [Place Output Formats](Output.md) for details on each format. (Default: html)
+See [Place Output Formats](Output.md) for details on each format. (Default: jsonv2)
* `json_callback=<string>`
e.g. `gb` for the United Kingdom, `de` for Germany.
Each place in Nominatim is assigned to one country code based
-on `admin_level=2` tags, in rare cases to none (for example in
-international waters outside any country).
+on OSM country boundaries. In rare cases a place may not be in any country
+at all, for example, in international waters.
* `exclude_place_ids=<place_id,[place_id],[place_id]`
If you do not want certain OSM objects to appear in the search
result, give a comma separated list of the `place_id`s you want to skip.
-This can be used to broaden search results. For example, if a previous
-query only returned a few results, then including those here would cause
-the search to return other, less accurate, matches (if possible).
+This can be used to retrieve additional search results. For example, if a
+previous query only returned a few results, then including those here would
+cause the search to return other, less accurate, matches (if possible).
* `limit=<integer>`
* `bounded=[0|1]`
-When a viewbox is given, restrict the result to items contained with that
+When a viewbox is given, restrict the result to items contained within that
viewbox (see above). When `viewbox` and `bounded=1` are given, an amenity
-only search is allowed. In this case, give the special keyword for the
-amenity in square brackets, e.g. `[pub]`. (Default: 0)
+only search is allowed. Give the special keyword for the amenity in square
+brackets, e.g. `[pub]` and a selection of objects of this type is returned.
+There is no guarantee that the result is complete. (Default: 0)
### Polygon output
* `polygon_threshold=0.0`
-Simplify the output geometry before returning. The parameter is the
+Return a simplified version of the output geometry. The parameter is the
tolerance in degrees with which the geometry may differ from the original
geometry. Topology is preserved in the result. (Default: 0.0)
* `dedupe=[0|1]`
Sometimes you have several objects in OSM identifying the same place or
-object in reality. The simplest case is a street being split in many
+object in reality. The simplest case is a street being split into many
different OSM ways due to different characteristics. Nominatim will
attempt to detect such duplicates and only return one match unless
this parameter is set to 0. (Default: 1)
-
-
* `debug=[0|1]`
Output assorted developer debug information. Data on internals of Nominatim's
## Prerequisites for testing and documentation
-The Nominatim tests suite consists of behavioural tests (using behave) and
+The Nominatim test suite consists of behavioural tests (using behave) and
unit tests (using PHPUnit). It has the following additional requirements:
* [behave test framework](https://behave.readthedocs.io) >= 1.2.5
Some of the behavioural test expect a test database to be present. You need at
least 2GB RAM and 10GB disk space to create the database.
-First create a separate directory for the test DB and Fetch the test planet
+First create a separate directory for the test DB and fetch the test planet
data and the Tiger data for South Dakota:
```
# OSM Data Import
-OSM data is initially imported using osm2pgsql. Nominatim uses its own data
-output style 'gazetteer', which differs from the output style created for
-map rendering.
+OSM data is initially imported using [osm2pgsql](https://osm2pgsql.org).
+Nominatim uses its own data output style 'gazetteer', which differs from the
+output style created for map rendering.
## Database Layout
## Search rank
The search rank describes the extent and importance of a place. It is used
-when ranking search result. Simply put, if there are two results for a
+when ranking search results. Simply put, if there are two results for a
search query which are otherwise equal, then the result with the _lower_
search rank will be appear higher in the result list.
## PHP Unit Tests (`test/php`)
-Unit tests can be found in the php/ directory and tests selected php functions.
+Unit tests can be found in the php/ directory. They test selected php functions.
Very low coverage.
To execute the test suite run
### API Tests (`test/bdd/api`)
These tests are meant to test the different API endpoints and their parameters.
-They require a to import several datasets into a test database.
+They require to import several datasets into a test database.
See the [Development Setup chapter](Development-Environment.md#preparing-the-test-database)
for instructions on how to set up this database.
These tests check the import and update of the Nominatim database. They do not
test the correctness of osm2pgsql. Each test will write some data into the `place`
-table (and optionally `the planet_osm_*` tables if required) and then run
+table (and optionally the `planet_osm_*` tables if required) and then run
Nominatim's processing functions on that.
These tests need to create their own test databases. By default they will be
### Import Tests (`test/bdd/osm2pgsql`)
These tests check that data is imported correctly into the place table. They
-use the same template database as the Indexing tests, so the same remarks apply.
+use the same template database as the DB Creation tests, so the same remarks apply.
The __data import__ stage reads the raw OSM data and extracts all information
that is useful for geocoding. This part is done by osm2pgsql, the same tool
that can also be used to import a rendering database. It uses the special
-gazetteer output plugin in `osm2pgsql/output-gazetter.[ch]pp`. The result of
+gazetteer output plugin in `osm2pgsql/src/output-gazetter.[ch]pp`. The result of
the import can be found in the database table `place`.
The __address computation__ or __indexing__ stage takes the data from `place`
and adds additional information needed for geocoding. It ranks the places by
importance, links objects that belong together and computes addresses and
the search index. Most of this work is done in PL/pgSQL via database triggers
-and can be found in the file `sql/functions.sql`.
+and can be found in the files in the `sql/functions/` directory.
The __search frontend__ implements the actual API. It takes search
and reverse geocoding queries from the user, looks up the data and
projects / nominatim.git / commitdiff