SQLite | How efficient is my code?

Well I'm pretty new to SQL. I know the standards but I don't know how to write efficient stuff with it.
What I got for testing purpose:
- The plugin checks on every BlockBreak (stone) if the player exists
- If not it creates the default set for this player
- If yes it sets stone +1 on that player

getValues() = Query which checks a ResultSet

- Three queries for every new set (it's also created on PlayerLogin if it doesn't exist but I got a command to delete a player, so 3 queries in that case)?
- Two queries for every stone.

Isn't that kinda inefficient in SQLite?

Code:java

 
 
 
@EventHandler
public void onBlockBrake(BlockBreakEvent event) {
Block blocktype = event.getBlock();
String playername = event.getPlayer().getName().toLowerCase();
if (blocktype.getType().equals(Material.STONE)) {
if (plugin.getValues(playername) == null) {
plugin.sqlite.query("INSERT INTO ore (playername, stone) VALUES('"+playername+"', '0');");
}
plugin.sqlite.query("UPDATE ore SET stone = stone + 1 WHERE playername = '" + playername + "'");
}
}
 

 

Thats really about as efficient and simple as you can get with SQlite. Shouldn't be an issue at all, if you find it to be an issue save to a list of pending queries and write them async every so often.

 

I mean: Imaging there are 100 players mining. That would be more than 200 queries/sec (depends on pickaxe).
I don't know much about about SQLite but is there a cache or something like that to avoid high HDD I/O?
If not, wouldn't it be the same as using a plain file to store that stuff?