Bukkit

hello, 

I know in some case database are faster, but i'm going to use the playerdata to write somes info of each player (about a write every 1 minute).

With a server of 4000 uniques player and around 20/30 active player at once, what is the best choice?  Database who's gonna put some delay of write/read or using flat file? I've read having thousand of files can slow down the boot time but is there any best choice in this case? 

Feel like for mycommand using mysql isnt the best ? 

To claim MySQL would add a significant delay would be incorrect. MySQL is literally designed for extremely fast responses and will likely net you faster responses than a flatfile ever would due to the optimizations of the nature of it. How do you think massive websites like Facebook function? It's literally the purpose of a database. If the MySQL does end up being slow, that is a result of the plugin developer's implementation, not MySQL itself.

The answer is simple. If it's small, use a flatfile. If it's big, use a database. Yours is clearly big. Anything over 5-10 players consistently at once I'd consider big.