Very cool that Ruby can get that much faster with relatively small changes. Even just the implicit return + array allocation tip is a useful one on its own.

MariaDB is a mysql based product like the Percona stuff right? I assume most users would switch to MySQL proper.

Postgres is often a better choice, but not an easy one for shops already in the mysql world.

My trick is to rotate subprojects so I am always procrastinating something.

You still have to eventually finish the last subproject, but even that might be procrastinating on something for your next project.