I'm importing the OSM planet to my PostgreSQL using the flat file option.
Now I have my database and my flat nodes file, I want to apply some diffs files.
After reading this :
Lastly, since you have to reimport for --flat-nodes, you should make sure to download a new Europe extract, and make sure to download PBF, not bzipped XML.
I understood I need to download the diff file and ALL planet file again. Is it correct? By importing without the flat file option and keeping all temp tables in database, I just need the diff file to do the update.
Please explain the correct process to apply diff updates using the flat nodes file.