This is a command-line option for the
mysqldump commands (arg: Optional).
This causes the binary log position and filename to be appended to the output. If equal to 1, will print it as a CHANGE MASTER command; if equal to 2, that command will be prefixed with a comment symbol. This option will turn --lock-all-tables on, unless --single-transaction is specified too (on servers before MariaDB 5.3 this will still take a global read lock for a short time at the beginning of the dump; don't forget to read about --single-transaction below). In all cases, any action on logs will happen at the exact moment of the dump. Option automatically turns --lock-tables off.