Few months ago I donwloaded full planet.osm dump and imported it in postgresql database via osm2pgsql. Later I removed the dump file. Thats why I don't know the timestamp of my current osm data. How can I get this timestamp?
If I will know this timestamp, how can I download and import to my postgresql database the diff between this timestamp and now?
P.S.: import the full dump again is bad idea, it is too slow.