### Wikipedia rankings
Wikipedia can be used as an optional auxiliary data source to help indicate
-the importance of osm features. Nominatim will work without this information
+the importance of OSM features. Nominatim will work without this information
but it will improve the quality of the results if this is installed.
This data is available as a binary download:
wget https://www.nominatim.org/data/wikipedia_redirect.sql.bin
Combined the 2 files are around 1.5GB and add around 30GB to the install
-size of nominatim. They also increase the install time by an hour or so.
+size of Nominatim. They also increase the install time by an hour or so.
*NOTE:* you'll need to download the Wikipedia rankings before performing
the initial import of the data if you want the rankings applied to the
loaded data.
-### UK postcodes
+### Great Britain, USA postcodes
-Nominatim can use postcodes from an external source to improve searches that involve a UK postcode. This data can be optionally downloaded:
+Nominatim can use postcodes from an external source to improve searches that
+involve a GB or US postcode. This data can be optionally downloaded:
cd $NOMINATIM_SOURCE_DIR/data
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
-In its default setup, Nominatim is configured to import the full OSM data
+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 32GB of RAM and around 800GB of SSD hard disks. Depending on your
use case there are various ways to reduce the amount of data imported. This
### Using an extract
If you only need geocoding for a smaller region, then precomputed extracts
-are a good way to reduce the database size.
-[Geofabrik](https://download.geofabrik.de) offers extracts for most countries
-and also daily updates which can be used with the update process described
+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
-[other providers for extracts](https://wiki.openstreetmap.org/wiki/Planet.osm#Downloading)
+[other providers for extracts](https://wiki.openstreetmap.org/wiki/Planet.osm#Downloading).
-Please be aware that some extracts are not exactly cut along the country
-boundaries. As a result some parts of the boundary may be missing and
-Nominatim cannot compute the areas as a result.
+Please be aware that some extracts are not cut exactly along the country
+boundaries. As a result some parts of the boundary may be missing which means
+that Nominatim cannot compute the areas for some administrative areas.
+
+### Dropping Data Required for Dynamic Updates
+
+About half of the data in Nominatim's database is not really used for serving
+the API. It is only there to allow the data to be updated from the latest
+changes from OSM. For many uses these dynamic updates are not really required.
+If you don't plan to apply updates, the dynamic part of the database can be
+safely dropped using the following command:
+
+```
+./utils/setup.php --drop
+```
+
+Note that you still need to provide for sufficient disk space for the initial
+import. So this option is particularly interesting if you plan to transfer the
+database or reuse the space later.
### Reverse-only Imports
If you only want to use the Nominatim database for reverse lookups or
if you plan to use the installation only for exports to a
-[photon](http://photon.komoot.de/) database, then you can set up a database
+[photon](https://photon.komoot.de/) database, then you can set up a database
without search indexes. Add `--reverse-only` to your setup command above.
This saves about 5% of disk space.
boundaries, places, streets, addresses and POI data. There are also other
import styles available which only read selected data:
-
-
-style Import time DB size after drop
-admin 5h 189 GB 20 GB
-street
-address
-full
+* **settings/import-admin.style**
+ Only import administrative boundaries and places.
+* **settings/import-street.style**
+ Like the admin style but also adds streets.
+* **settings/import-address.style**
+ Import all data necessary to compute addresses down to house number level.
+* **settings/import-full.style**
+ Default style that also includes points of interest.
+
+The style can be changed with the configuration `CONST_Import_Style`.
+
+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 32GB 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.
+
+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
You can also customize the styles further. For an description of the
-style format see [the developement section](../develop/Import.md).
+style format see [the development section](../develop/Import.md).
## Initial import of the data
**Important:** 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:
+Download the data to import and load the data with the following command
+from the build directory:
```sh
./utils/setup.php --osm-file <data file> --all [--osm2pgsql-cache 28000] 2>&1 | tee setup.log
2/3 of RAM available. If your machine starts swapping reduce the size.
Computing word frequency for search terms can improve the performance of
-forward geocoding in particular under high load as it helps Postgres' query
+forward geocoding in particular under high load as it helps PostgreSQL's query
planner to make the right decisions. To recompute word counts run:
```sh
`data-source/us-tiger/README.md` explains how the data got preprocessed.
- 2. Import the data into your Nominatim database:
+ 2. Import the data into your Nominatim database:
./utils/setup.php --import-tiger-data
## Updates
-There are many different possibilities to update your Nominatim database.
+There are many different ways to update your Nominatim database.
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`.
If you want a different update source you will need to add some settings
to `settings/local.php`. For example, to use the daily country extracts
-diffs for Ireland from geofabrik add the following:
+diffs for Ireland from Geofabrik add the following:
// base URL of the replication service
@define('CONST_Replication_Url', 'https://download.geofabrik.de/europe/ireland-and-northern-ireland-updates');
It outputs the date where updates will start. Recheck that this date is
what you expect.
-The --init-updates command needs to be rerun whenever the replication service
+The `--init-updates` command needs to be rerun whenever the replication service
is changed.
#### Updating Nominatim
projects / nominatim.git / blobdiff