From 4c10294a29b4019588fbed4b0c8c595b2f909583 Mon Sep 17 00:00:00 2001 From: Sarah Hoffmann Date: Tue, 4 Dec 2018 22:22:19 +0100 Subject: [PATCH] document import style variants --- docs/admin/Import-and-Update.md | 57 +++++++++++++++++++++++++++------ 1 file changed, 47 insertions(+), 10 deletions(-) diff --git a/docs/admin/Import-and-Update.md b/docs/admin/Import-and-Update.md index 179b729e..bebc3645 100644 --- a/docs/admin/Import-and-Update.md +++ b/docs/admin/Import-and-Update.md @@ -58,10 +58,56 @@ Nominatim can use postcodes from an external source to improve searches that inv cd $NOMINATIM_SOURCE_DIR/data wget https://www.nominatim.org/data/gb_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. +[Geofabrik](https://download.geofabrik.de) offers extracts for most countries +and also 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 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. + +### 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 +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: + + + +style Import time DB size after drop +admin 5h 189 GB 20 GB +street +address +full + +You can also customize the styles further. For an description of the +style format see [the developement 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: @@ -98,15 +144,6 @@ you also need to enable these key phrases like this: Note that this command downloads the phrases from the wiki link above. -### 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 -without search indexes. Add `--reverse-only` to your setup command above. - -This saves about 5% of disk space. - ## Installing Tiger housenumber data for the US -- 2.45.1