--i-am-a-dummy Synonym for option --safe-updates, -U
Yes, believe it or not, MySQL has a switch that is called “I-am-a-dummy”. It is an alias for another switch, –safe-updates
--safe-updates Only allow UPDATE and DELETE that uses keys.
Now that is very handy. Using this it basically means you are not allowed to perform any update or delete in any table, without using keys. This will basically help you not do any accidental deletions or changes on a wide range of records, or just wipe out your whole table.
Smart and funny.