I don't think so, many queries will be if you;re updating sql data after every kill
Let's assume for a 32 players full server and a 20min for ex maptime, so in this 20 mins you will have 32*nr of kills queries to run.. kind a huge ammount of jobs for the mysql server but if you're saving at the.moment when player leaves the server then the ammount of queries will be much lower since in 20mins how much players can you have that leaves or joins the server? For ex in 5 min with a round time of 2 min can be made ~100kills and this for a non csdm server(nr of kills will be much greater on this), as an oposite will you have 100 connections/ disconnections in 5min? Much likely no
Also in threaded queries you don't have to free the query handle