Additional Data Sources

This guide explains how data sources other than OpenStreetMap mentioned in the install instructions got obtained and converted.

Country grid

Nominatim uses pre-generated country borders data. In case one imports only a subset of a country. And to assign each place a partition. Nominatim database tables are split into partitions for performance.

More details in osm-search/country-grid-data.

US Census TIGER

For the United States you can choose to import additonal street-level data. The data isn't mixed into OSM data but queried as fallback when no OSM result can be found.

More details in osm-search/TIGER-data.

GB postcodes

For Great Britain you can choose to import Royalmail postcode centroids.

More details in osm-search/gb-postcode-data.

Wikipedia & Wikidata rankings

Nominatim can import "importance" data of place names. This greatly improves ranking of results.

More details in osm-search/wikipedia-wikidata.