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MySQL 8.0 Reference Manual  /  ...  /  mysql_upgrade — Check and Upgrade MySQL Tables

Pre-General Availability Draft: 2018-03-23

4.4.5 mysql_upgrade — Check and Upgrade MySQL Tables

mysql_upgrade examines all tables in all databases for incompatibilities with the current version of MySQL Server. mysql_upgrade also upgrades the system tables so that you can take advantage of new privileges or capabilities that might have been added.

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 2.10.3, “Rebuilding or Repairing Tables or Indexes” for manual table repair strategies.

You should execute mysql_upgrade each time you upgrade MySQL.

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


On Windows Server 2008, Vista, and newer, you must run mysql_upgrade with administrator privileges. You can do this by running a Command Prompt as Administrator and running the command. Failure to do so may result in the upgrade failing to execute correctly.


You should always back up your current MySQL installation before performing an upgrade. See Section 7.2, “Database Backup Methods”.

Some upgrade incompatibilities may require special handling before you upgrade your MySQL installation and run mysql_upgrade. See Section 2.10.1, “Upgrading MySQL”, for instructions on determining whether any such incompatibilities apply to your installation and how to handle them.

To use mysql_upgrade, make sure that the server is running. Then invoke it like this to check and repair tables and to upgrade the system tables:

shell> mysql_upgrade [options]

After running mysql_upgrade, stop the server and restart it so that any changes made to the system tables take effect.

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

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

For local host connections on Unix, the --protocol=tcp option forces a connection using TCP/IP rather than the Unix socket file.

mysql_upgrade processes all tables in all databases, which 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.

For details about what table-checking operations entail, see the description of the FOR UPGRADE option of the CHECK TABLE statement (see Section, “CHECK TABLE Syntax”).

All checked and repaired tables are marked with the current MySQL version number. This ensures that next time you run mysql_upgrade with the same version of the server, it can tell whether there is any need to check or repair the table again.

mysql_upgrade also saves the MySQL version number in a file named mysql_upgrade_info in the data directory. This is used to quickly check whether all tables have been checked for this release so that table-checking can be skipped. To ignore this file and perform the check regardless, use the --force option.

mysql_upgrade checks user table rows and, for any row with an empty plugin column, sets that column 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.

mysql_upgrade does not upgrade the contents of the help tables. For upgrade instructions, see Section 5.1.11, “Server-Side Help”.

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. mysql_upgrade returns an error if a sys schema exists but has no version view, on the assumption that its absence indicates a user-created schema:

Error occurred: 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.

To upgrade in this case, remove or rename the existing sys schema first.

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

By default, mysql_upgrade runs as the MySQL root user. If the root password is expired when you run mysql_upgrade, you will see a message 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
Enter password: ****  <- enter root password here

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]

mysql_upgrade supports the following options, which can be specified on the command line or in the [mysql_upgrade] and [client] groups of an option file. For information about option files used by MySQL programs, see Section 4.2.6, “Using Option Files”.

Table 4.7 mysql_upgrade Options

Format Description Introduced
--bind-address Use specified network interface to connect to MySQL Server
--character-sets-dir Directory where character sets are installed
--compress Compress all information sent between client and server
--debug Write debugging log
--debug-check Print debugging information when program exits
--debug-info Print debugging information, memory, and CPU statistics when program exits
--default-auth Authentication plugin to use
--default-character-set Specify default character set
--defaults-extra-file Read named option file in addition to usual option files
--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 version of MySQL
--get-server-public-key Request RSA public key from server 8.0.3
--help Display help message and exit
--host Connect to MySQL server on given host
--login-path Read login path options from .mylogin.cnf
--max-allowed-packet Maximum packet length to send to or receive from server
--net-buffer-length Buffer size for TCP/IP and socket communication
--no-defaults Read no option files
--password Password to use when connecting to server
--pipe On Windows, connect to server using named pipe
--plugin-dir Directory where plugins are installed
--port TCP/IP port number for connection
--print-defaults Print default options
--protocol Connection protocol to use
--server-public-key-path Path name to file containing RSA public key 8.0.4
--shared-memory-base-name The name of shared memory to use for shared-memory connections
--skip-sys-schema Do not install or upgrade the sys schema
--socket For connections to localhost, the Unix socket file to use
--ssl-ca File that contains list of trusted SSL Certificate Authorities
--ssl-capath Directory that contains trusted SSL Certificate Authority certificate files
--ssl-cert File that contains X509 certificate
--ssl-cipher List of permitted ciphers for connection encryption
--ssl-crl File that contains certificate revocation lists
--ssl-crlpath Directory that contains certificate revocation list files
--ssl-key File that contains X509 key
--ssl-mode Security state of connection to server
--tls-version Protocols permitted for encrypted connections
--upgrade-system-tables Update only system tables, not data
--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

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