We usually use original geometries for OSM because the address computation that Nominatim does relies heavily on spatial relation of OSM objects, streets inside cities, one admin boundary inside another etc.
Polygons with rank_address = 0 do not take part in address computation. They are only used to search for and (rarely) for reverse lookup. Geometries do not need to be precise for that because spatial relation does not matter. OSM has some very large polygons of natural features with sizes of more than 10MB. Simplify these polygons to keep the database and indexes smaller.
We usually use original geometries for OSM because the address computation that Nominatim does relies heavily on spatial relation of OSM objects, streets inside cities, one admin boundary inside another etc.
Polygons with rank_address = 0 do not take part in address computation. They are only used to search for and (rarely) for reverse lookup. Geometries do not need to be precise for that because spatial relation does not matter. OSM has some very large polygons of natural features with sizes of more than 10MB. Simplify these polygons to keep the database and indexes smaller.
Closes #2987.