

4.4.7 mysql_upgrade — Check and Upgrade MySQL Tables

Each time you upgrade MySQL, you should execute mysql_upgrade, which looks for incompatibilities with the upgraded MySQL server:

If mysql_upgrade finds that a table has a possible incompatibility, it performs a table check and, if problems are found, attempts a table repair. If the table cannot be repaired, see Section 2.11.12, “Rebuilding or Repairing Tables or Indexes” for manual table repair strategies.

mysql_upgrade communicates directly with the MySQL server, sending it the SQL statements required to perform an upgrade.


In MySQL 5.7.11, the default --early-plugin-load value is the name of the keyring_file plugin library file, causing that plugin to be loaded by default. In MySQL 5.7.12 and higher, the default --early-plugin-load value is empty; to load the keyring_file plugin, you must explicitly specify the option with a value naming the keyring_file plugin library file.

InnoDB tablespace encryption requires that the keyring plugin to be used be loaded prior to InnoDB initialization, so this change of default --early-plugin-load value introduces an incompatibility for upgrades from 5.7.11 to 5.7.12 or higher. Administrators who have encrypted InnoDB tablespaces must take explicit action to ensure continued loading of the keyring plugin: Start the server with an --early-plugin-load option that names the plugin library file. For additional information, see Section, “Keyring Plugin Installation”.


If you upgrade to MySQL 5.7.2 or later from a version older than 5.7.2, a change to the mysql.user table requires a special sequence of steps to perform an upgrade using mysql_upgrade. For details, see Section 2.11.3, “Changes in MySQL 5.7”.





Some upgrade incompatibilities may require special handling before upgrading your MySQL installation and running mysql_upgrade. See Section 2.11, “Upgrading MySQL”, for instructions on determining whether any such incompatibilities apply to your installation and how to handle them.

Use mysql_upgrade like this:

  1. Ensure that the server is running.

  2. Invoke mysql_upgrade to upgrade the system tables in the mysql schema and check and repair tables in other schemas:

    mysql_upgrade [options]
  3. Stop the server and restart it so that any system table changes take effect.

If you have multiple MySQL server instances to upgrade, invoke mysql_upgrade with connection parameters appropriate for connecting to each of the desired servers. For example, with servers running on the local host on parts 3306 through 3308, upgrade each of them by connecting to the appropriate port:

mysql_upgrade --protocol=tcp -P 3306 [other_options]
mysql_upgrade --protocol=tcp -P 3307 [other_options]
mysql_upgrade --protocol=tcp -P 3308 [other_options]


By default, mysql_upgrade runs as the MySQL root user. If the root password is expired when you run mysql_upgrade, it displays a message telling you that your password is expired and that mysql_upgrade failed as a result. To correct this, reset the root password to unexpire it and run mysql_upgrade again. First, connect to the server as root:

shell> mysql -u root -p

Reset the password using ALTER USER:

mysql> ALTER USER USER() IDENTIFIED BY 'root-password';

Then exit mysql and run mysql_upgrade again:

shell> mysql_upgrade [options]

If you run the server with the disabled_storage_engines system variable set to disable certain storage engines (for example, MyISAM), mysql_upgrade might fail with an error like this:

mysql_upgrade: [ERROR] 3161: Storage engine MyISAM is disabled
(Table creation is disallowed).

To handle this, restart the server with disabled_storage_engines disabled. Then you should be able to run mysql_upgrade successfully. After that, restart the server with disabled_storage_engines set to its original value.

Unless invoked with the --upgrade-system-tables option, mysql_upgrade processes all tables in all user schemas as necessary. Table checking might take a long time to complete. Each table is locked and therefore unavailable to other sessions while it is being processed. Check and repair operations can be time-consuming, particularly for large tables. Table checking uses the FOR UPGRADE option of the CHECK TABLE statement. For details about what this option entails, see Section, “CHECK TABLE Statement”.

mysql_upgrade marks all checked and repaired tables with the current MySQL version number. This ensures that the next time you run mysql_upgrade with the same version of the server, it can be determined whether there is any need to check or repair a given table again.



Support for pre-4.1 password hashing and mysql_old_password has been removed, so mysql_upgrade sets empty plugin values to 'mysql_native_password' if the credentials use a hash format compatible with that plugin. Rows with a pre-4.1 password hash must be upgraded manually. For account upgrade instructions, see Section, “Migrating Away from Pre-4.1 Password Hashing and the mysql_old_password Plugin”.

mysql_upgrade does not upgrade the contents of the time zone tables or help tables. For upgrade instructions, see Section 5.1.13, “MySQL Server Time Zone Support”, and Section 5.1.14, “Server-Side Help Support”.

Unless invoked with the --skip-sys-schema option, mysql_upgrade installs the sys schema if it is not installed, and upgrades it to the current version otherwise. An error occurs if a sys schema exists but has no version view, on the assumption that its absence indicates a user-created schema:

A sys schema exists with no sys.version view. If
you have a user created sys schema, this must be renamed for the
upgrade to succeed.


mysql_upgrade checks for partitioned InnoDB tables that were created using the generic partitioning handler and attempts to upgrade them to InnoDB native partitioning. (Bug #76734, Bug #20727344) You can upgrade such tables individually in the mysql client using the ALTER TABLE ... UPGRADE PARTITIONING SQL statement.


Table 4.11 mysql_upgrade Options

Option Name Description Introduced
--compress Compress all information sent between client and server
--debug Write debugging log
--debug-check Print debugging information when program exits
--default-auth Authentication plugin to use
--default-character-set Specify default character set
--defaults-file Read only named option file
--defaults-group-suffix Option group suffix value
--force Force execution even if mysql_upgrade has already been executed for current MySQL version
--help Display help message and exit
--host Host on which MySQL server is located
--login-path Read login path options from .mylogin.cnf
--no-defaults Read no option files
--password Password to use when connecting to server
--plugin-dir Directory where plugins are installed
--port TCP/IP port number for connection
--print-defaults Print default options
--protocol Transport protocol to use
--shared-memory-base-name Shared-memory name for shared-memory connections (Windows only)
--skip-sys-schema Do not install or upgrade sys schema
--socket Unix socket file or Windows named pipe to use
--ssl Enable connection encryption
--ssl-cert File that contains X.509 certificate
--ssl-cipher Permissible ciphers for connection encryption
--ssl-crl File that contains certificate revocation lists
--ssl-key File that contains X.509 key
--ssl-mode Desired security state of connection to server 5.7.11
--tls-version Permissible TLS protocols for encrypted connections 5.7.10
--upgrade-system-tables Update only system tables, not user schemas
--user MySQL user name to use when connecting to server
--verbose Verbose mode
--version-check Check for proper server version
--write-binlog Write all statements to binary log