LEFT JOIN is supposed to be faster than a NOT IN query. This is what I've read online. But practically, this seems to be opposite. I have the following query here, INSERT IGNORE INTO callrequests ...
Recently, I moved from standard MySQL to Percona, and used the Percona Wizard to generate my.cnf. However, I can see that, by default, the generated settings for my.cnf use query_cache_type = 0. ...