# OSM Dump

By: Just van den Broecke - version: July 29, 2021

This directory contains a Postgres dump file with OpenStreetMap data
processed with Imposm3 plus supporting files like this README. 

Dumps should be found under https://data.nlextract.nl/beta/osm-planet/
Each subdir provides data by date YYMMDD. Data is processed within the geotoko.nl
ETL environment, De Geofabriek.

Specifics below.

## Source Data

* PBF file from http://download.geofabrik.de
* testing: Oberbayern: http://download.geofabrik.de/europe/germany/bayern/oberbayern-latest.osm.pbf
* production: entire world Planet File

## Imposm3

* run in Docker. image: python:3.8-slim-buster
* imposm3 version: 0.11.1
* installed binary: https://github.com/omniscale/imposm3/releases/download/v0.11.1/imposm-0.11.1-linux-x86-64.tar.gz
* binary contains all dependencies like libgeos etc
* writes data in schema called "import"
* command: imposm import -mapping ${IMPOSM_MAPPING_FILE} -read ${DOWNLOAD_FILE} -write -connection postgis://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${POSTGRES_HOST}/${POSTGRES_DB} 
* various imposm table-mapping YAML files, find the used mapping file in this directory

## Postgres/PostGIS

* DB name: osmimp, same for user and password
* using Docker Image: postgis/postgis:11-3.1-alpine
* dumped with Postgres custom dump format, mainly as SQL dump size for planet would be much too big
* pg_dump options: --format custom --no-password --no-privileges --no-acl --no-owner -j 4 -n import
* only the schema 'import' is dumped (-n import)
* also the schema SQL for that schema is provided
* geometries are in WGS 84 / Pseudo-Mercator - EPSG:3857

## Questions

just@justobjects.nl