MySQL “SET NAMES” near the top of the slow query log

Question

On a recently launched site, I noticed that, well over the actual heavy queries on the site, the most costly request, out of several million queries, is actually SET NAMES, whic

Answer 1

If all queries are slow, SET NAMES can have a very low priority on the server, and therefore wait until the load dies down. If you have a lot of other queries that take a long time executing, you might want to try to optimize those first.

Another solution to this "problem", could be adding this to your my.cnf on the server:

[mysqld]
init-connect = 'SET NAMES utf8'

This makes sure the character set is set to UTF-8 when a client connects, so the client does not have to wait for the result of this "query". You probably want to disable the SET NAMES query in your software.

Mainly, I wouldn't worry too much unless you really have A LOT of SET NAMES that takes this long.