Importuję sobie plik:
osm2pgsql --create --database osm_diff --prefix diff --cache 2000 /tmp/osm/poland-latest.osm.pbf_poly.pbf
WGS84:
osm_diff=# SELECT ST_Length(way) FROM diff_line WHERE osm_id='169022564';
st_length
-------------------
0.999999999999999
0.248564468122308
(2 rows)
Mercator:
osm_diff=# SELECT ST_Length(way) FROM diff_line WHERE osm_id='169022564';
st_length
------------------
99999.9999999999
48931.7186307075
(2 rows)
Przy imporcie za pomocą osmosis jest normalnie:
osm_diff=# SELECT ST_Length(linestring) FROM ways WHERE id='169022564';
st_length
-----------------
1.2485644681223
(1 row)