I have a snapshot of all of OSM for a given date (conveniently called planet-XXXXXX.osm.pbf) and the compressed version is 62GB. And the format is optimized for reading certain chunks (as well as updating with new data). Plus there are libraries that do the heavy lifting for you in little time at all.
The size is really not as big of an issue as you think it is.
I have a snapshot of all of OSM for a given date (conveniently called planet-XXXXXX.osm.pbf) and the compressed version is 62GB. And the format is optimized for reading certain chunks (as well as updating with new data). Plus there are libraries that do the heavy lifting for you in little time at all.
The size is really not as big of an issue as you think it is.