MySQLTuner : MySQLTuner is a script written in Perl that will assist you with your MySQL configuration and make recommendations for increased performance and stabi...
Use The Index, Luke! : A tutorial covering SQL indexing and SQL tuning for developers: avoiding unnecessary details about database internals.
SQL indexing is the most effect...
Phantomas : PhantomJS-based web performance metrics collector and monitoring tool
Beekeeper Studio : Open Source cross-platform SQL Editor and Database Manager. Use Beekeeper Studio to query and manage your relational databases, like MySQL, Postgres, ...