osm2vectortiles/docs/import-export-process.md

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title: Import and Export Process
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# Import and Export Process

### Import

The import process imports the data from all [data sources](/docs/data-sources.html) into a single PostGIS database.
The figure below shows which data source gets imported with which import tool.

![Import Step](/media/import_package_flow.png)

The `import-sql` container adds helper sql functions, which are used inside the [data style](https://github.com/osm2vectortiles/osm2vectortiles/blob/master/open-streets.tm2source/data.yml).

### Export

For generating the vector tiles the tilelive tool [tl](https://github.com/mojodna/tl) is used which wraps around Mapnik.
The tm2source project defines all feature sets (layers) and is transformed into a Mapnik XML stylesheet by the tilelive-tm2source provider.
Tilelive-bridge calls Mapnik with the generated stylesheet and  hands  the  generated  data  over  to node-mbtiles, which  stores  the  vector  tiles  in  a MBTiles container.

![Export Step](/media/export_package_flow.png)