1 # Importing and Updating the Database
3 The following instructions explain how to create a Nominatim database
4 from an OSM planet file and how to keep the database up to date. It
5 is assumed that you have already successfully installed the Nominatim
6 software itself, if not return to the [installation page](Installation.md).
8 ## Configuration setup in settings/local.php
10 The Nominatim server can be customized via the file `settings/local.php`
11 in the build directory. Note that this is a PHP file, so it must always
16 without any leading spaces.
18 There are lots of configuration settings you can tweak. Have a look
19 at `settings/default.php` for a full list. Most should have a sensible default.
23 If you plan to import a large dataset (e.g. Europe, North America, planet),
24 you should also enable flatnode storage of node locations. With this
25 setting enabled, node coordinates are stored in a simple file instead
26 of the database. This will save you import time and disk storage.
27 Add to your `settings/local.php`:
29 @define('CONST_Osm2pgsql_Flatnode_File', '/path/to/flatnode.file');
31 Replace the second part with a suitable path on your system and make sure
32 the directory exists. There should be at least 40GB of free space.
34 ## Downloading additional data
36 ### Wikipedia/Wikidata rankings
38 Wikipedia can be used as an optional auxiliary data source to help indicate
39 the importance of OSM features. Nominatim will work without this information
40 but it will improve the quality of the results if this is installed.
41 This data is available as a binary download:
43 cd $NOMINATIM_SOURCE_DIR/data
44 wget https://www.nominatim.org/data/wikimedia_importance.sql.gz
46 The file is about 1GB and it adds around 10GB to the install
47 size of Nominatim. They also increase the install time by an hour or so.
49 *NOTE:* if you forgot to download the wikipedia rankings, you can also add
50 them after the import by running `./utils/setup.php --import-wikipedia-articles`
51 and then `./utils/update.php --recompute-importance`.
53 ### Great Britain, USA postcodes
55 Nominatim can use postcodes from an external source to improve searches that
56 involve a GB or US postcode. This data can be optionally downloaded:
58 cd $NOMINATIM_SOURCE_DIR/data
59 wget https://www.nominatim.org/data/gb_postcode_data.sql.gz
60 wget https://www.nominatim.org/data/us_postcode_data.sql.gz
62 ## Choosing the Data to Import
64 In its default setup Nominatim is configured to import the full OSM data
65 set for the entire planet. Such a setup requires a powerful machine with
66 at least 32GB of RAM and around 800GB of SSD hard disks. Depending on your
67 use case there are various ways to reduce the amount of data imported. This
68 section discusses these methods. They can also be combined.
72 If you only need geocoding for a smaller region, then precomputed extracts
73 are a good way to reduce the database size and import time.
74 [Geofabrik](https://download.geofabrik.de) offers extracts for most countries.
75 They even have daily updates which can be used with the update process described
77 [other providers for extracts](https://wiki.openstreetmap.org/wiki/Planet.osm#Downloading).
79 Please be aware that some extracts are not cut exactly along the country
80 boundaries. As a result some parts of the boundary may be missing which means
81 that Nominatim cannot compute the areas for some administrative areas.
83 ### Dropping Data Required for Dynamic Updates
85 About half of the data in Nominatim's database is not really used for serving
86 the API. It is only there to allow the data to be updated from the latest
87 changes from OSM. For many uses these dynamic updates are not really required.
88 If you don't plan to apply updates, the dynamic part of the database can be
89 safely dropped using the following command:
92 ./utils/setup.php --drop
95 Note that you still need to provide for sufficient disk space for the initial
96 import. So this option is particularly interesting if you plan to transfer the
97 database or reuse the space later.
99 ### Reverse-only Imports
101 If you only want to use the Nominatim database for reverse lookups or
102 if you plan to use the installation only for exports to a
103 [photon](https://photon.komoot.de/) database, then you can set up a database
104 without search indexes. Add `--reverse-only` to your setup command above.
106 This saves about 5% of disk space.
108 ### Filtering Imported Data
110 Nominatim normally sets up a full search database containing administrative
111 boundaries, places, streets, addresses and POI data. There are also other
112 import styles available which only read selected data:
114 * **settings/import-admin.style**
115 Only import administrative boundaries and places.
116 * **settings/import-street.style**
117 Like the admin style but also adds streets.
118 * **settings/import-address.style**
119 Import all data necessary to compute addresses down to house number level.
120 * **settings/import-full.style**
121 Default style that also includes points of interest.
123 The style can be changed with the configuration `CONST_Import_Style`.
125 To give you an idea of the impact of using the different styles, the table
126 below gives rough estimates of the final database size after import of a
127 2018 planet and after using the `--drop` option. It also shows the time
128 needed for the import on a machine with 32GB RAM, 4 CPUS and SSDs. Note that
129 the given sizes are just an estimate meant for comparison of style requirements.
130 Your planet import is likely to be larger as the OSM data grows with time.
132 style | Import time | DB size | after drop
133 ----------|--------------|------------|------------
134 admin | 5h | 190 GB | 20 GB
135 street | 42h | 400 GB | 180 GB
136 address | 59h | 500 GB | 260 GB
137 full | 80h | 575 GB | 300 GB
139 You can also customize the styles further. For an description of the
140 style format see [the development section](../develop/Import.md).
142 ## Initial import of the data
144 **Important:** first try the import with a small extract, for example from
145 [Geofabrik](https://download.geofabrik.de).
147 Download the data to import and load the data with the following command
148 from the build directory:
151 ./utils/setup.php --osm-file <data file> --all [--osm2pgsql-cache 28000] 2>&1 | tee setup.log
154 The `--osm2pgsql-cache` parameter is optional but strongly recommended for
155 planet imports. It sets the node cache size for the osm2pgsql import part
156 (see `-C` parameter in osm2pgsql help). As a rule of thumb, this should be
157 about the same size as the file you are importing but never more than
158 2/3 of RAM available. If your machine starts swapping reduce the size.
160 Computing word frequency for search terms can improve the performance of
161 forward geocoding in particular under high load as it helps PostgreSQL's query
162 planner to make the right decisions. To recompute word counts run:
165 ./utils/update.php --recompute-word-counts
168 This will take a couple of hours for a full planet installation. You can
169 also defer that step to a later point in time when you realise that
170 performance becomes an issue. Just make sure that updates are stopped before
171 running this function.
173 If you want to be able to search for places by their type through
174 [special key phrases](https://wiki.openstreetmap.org/wiki/Nominatim/Special_Phrases)
175 you also need to enable these key phrases like this:
177 ./utils/specialphrases.php --wiki-import > specialphrases.sql
178 psql -d nominatim -f specialphrases.sql
180 Note that this command downloads the phrases from the wiki link above.
183 ## Installing Tiger housenumber data for the US
185 Nominatim is able to use the official [TIGER](https://www.census.gov/geo/maps-data/data/tiger.html)
186 address set to complement the OSM house number data in the US. You can add
187 TIGER data to your own Nominatim instance by following these steps. The
188 entire US adds about 10GB to your database.
190 1. Get preprocessed TIGER 2019 data and unpack it into the
191 data directory in your Nominatim sources:
194 wget https://nominatim.org/data/tiger2019-nominatim-preprocessed.tar.gz
195 tar xf tiger2019-nominatim-preprocessed.tar.gz
197 `data-source/us-tiger/README.md` explains how the data got preprocessed.
199 2. Import the data into your Nominatim database:
201 ./utils/setup.php --import-tiger-data
203 3. Enable use of the Tiger data in your `settings/local.php` by adding:
205 @define('CONST_Use_US_Tiger_Data', true);
207 4. Apply the new settings:
210 ./utils/setup.php --create-functions --enable-diff-updates --create-partition-functions
216 There are many different ways to update your Nominatim database.
217 The following section describes how to keep it up-to-date with Pyosmium.
218 For a list of other methods see the output of `./utils/update.php --help`.
220 #### Installing the newest version of Pyosmium
222 It is recommended to install Pyosmium via pip. Make sure to use python3.
223 Run (as the same user who will later run the updates):
226 pip3 install --user osmium
229 Nominatim needs a tool called `pyosmium-get-updates` which comes with
230 Pyosmium. You need to tell Nominatim where to find it. Add the
231 following line to your `settings/local.php`:
233 @define('CONST_Pyosmium_Binary', '/home/user/.local/bin/pyosmium-get-changes');
235 The path above is fine if you used the `--user` parameter with pip.
236 Replace `user` with your user name.
238 #### Setting up the update process
240 Next the update needs to be initialised. By default Nominatim is configured
241 to update using the global minutely diffs.
243 If you want a different update source you will need to add some settings
244 to `settings/local.php`. For example, to use the daily country extracts
245 diffs for Ireland from Geofabrik add the following:
247 // base URL of the replication service
248 @define('CONST_Replication_Url', 'https://download.geofabrik.de/europe/ireland-and-northern-ireland-updates');
249 // How often upstream publishes diffs
250 @define('CONST_Replication_Update_Interval', '86400');
251 // How long to sleep if no update found yet
252 @define('CONST_Replication_Recheck_Interval', '900');
254 To set up the update process now run the following command:
256 ./utils/update.php --init-updates
258 It outputs the date where updates will start. Recheck that this date is
261 The `--init-updates` command needs to be rerun whenever the replication service
264 #### Updating Nominatim
266 The following command will keep your database constantly up to date:
268 ./utils/update.php --import-osmosis-all
270 (Note that even though the old name "import-osmosis-all" has been kept for compatibility reasons, Osmosis is not required to run this - it uses pyosmium behind the scenes.)
272 If you have imported multiple country extracts and want to keep them
273 up-to-date, have a look at the script in
274 [issue #60](https://github.com/openstreetmap/Nominatim/issues/60).