I am working on postgresql for several days
I imported the data from open street map (osm)
everything works well until I translate the geometry type
the value it gives is very large. I have no idea what it is
The coordinates are in the Web Mercator projection (3857) not in lat-long (4326). This projection uses meters from a reference point (lat-long 0;0)
Some tools such as osm2pgsql
will use the Web Mercator by default.