mysqldump --master-data flag

The --master-data flag is a useful option when using the mysqldump utility for backing up a MySQL database. This flag adds a CHANGE MASTER TO statement in the backup file, which can be used to set the binary log position for replication when restoring the backup.

What happens when the flag is used?

When --master-data is used, mysqldump includes the binary log coordinates in the output file. These coordinates specify the position of the binary log file and the position within that file where the backup was taken. This information can be used to set up replication or to recover the database to a specific point in time.

How to use the flag

Here's an example of how to use the --master-data flag:

mysqldump -u root -p --master-data database_name > database_name.sql

In this example, the --master-data flag is used in combination with the mysqldump utility to backup the database_name database. The output is saved to a file named database_name.sql.

It's important to note that the --master-data flag is only relevant for databases that use binary logging for replication. If binary logging is not enabled, the --master-data flag has no effect.