Did you just run an UPDATE against your 10 million row users table without a WHERE clause? Did you know that in MySQL 5.5 that sometimes you can recover from a bad UPDATE statement? This is possible if you are running in binlog_format=ROW !
Imagine this scenario:
CREATE TABLE `t1` ( `c1` int(11) NOT NULL AUTO_INCREMENT, `c2` varchar(10) NOT NULL, PRIMARY KEY (`c1`) ) ENGINE=InnoDB; INSERT INTO `t1` (`c2`) VALUES ('michael'), ('peter'), ('aamina');
We run an accidental UPDATE statement that changes a row:
UPDATE `t1` SET `c2` = 'tom' WHERE `c1` = 2;
If we examine this UPDATE using the Binary Logging format of STATEMENT the entry would look like: