X-Git-Url: https://git.openstreetmap.org./nominatim.git/blobdiff_plain/aa41b813b8575aea1657c74e2ee22bdb6fe707b1..765a932561d7c9b3dd6954b41b2e34e476fe2a26:/docs/admin/Import-and-Update.md diff --git a/docs/admin/Import-and-Update.md b/docs/admin/Import-and-Update.md index 847aa37d..257e5ebc 100644 --- a/docs/admin/Import-and-Update.md +++ b/docs/admin/Import-and-Update.md @@ -36,7 +36,7 @@ the directory exists. There should be at least 40GB of free space. ### 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: @@ -45,26 +45,108 @@ 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 +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 +section discusses these methods. They can also be combined. + +### Using an extract + +If you only need geocoding for a smaller region, then precomputed 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 +[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 +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](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. + +### Filtering Imported Data + +Nominatim normally sets up a full search database containing administrative +boundaries, places, streets, addresses and POI data. There are also other +import styles available which only read selected data: + +* **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 development section](../develop/Import.md). ## Initial import of the data -**Important:** first try the import with a small excerpt, for example from +**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 --all [--osm2pgsql-cache 28000] 2>&1 | tee setup.log @@ -77,7 +159,7 @@ about the same size as the file you are importing but never more than 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 @@ -115,7 +197,7 @@ entire US adds about 10GB to your database. `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 @@ -132,7 +214,7 @@ entire US adds about 10GB to your database. ## 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`. @@ -161,7 +243,7 @@ to update using the global minutely diffs. 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'); @@ -177,7 +259,7 @@ To set up the update process now run the following command: 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