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

Pre-General Availability Draft: 2017-08-16

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 5.1.10, “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

--bind-addressUse specified network interface to connect to MySQL Server
--character-sets-dirDirectory where character sets are installed
--compressCompress all information sent between client and server
--debugWrite debugging log
--debug-checkPrint debugging information when program exits
--debug-infoPrint debugging information, memory, and CPU statistics when program exits
--default-authAuthentication plugin to use
--default-character-setSpecify default character set
--defaults-extra-fileRead named option file in addition to usual option files
--defaults-fileRead only named option file
--defaults-group-suffixOption group suffix value
--forceForce execution even if mysql_upgrade has already been executed for current version of MySQL
--helpDisplay help message and exit
--hostConnect to MySQL server on given host
--login-pathRead login path options from .mylogin.cnf
--max-allowed-packetMaximum packet length to send to or receive from server
--net-buffer-lengthBuffer size for TCP/IP and socket communication
--no-defaultsRead no option files
--passwordPassword to use when connecting to server
--pipeOn Windows, connect to server using named pipe
--plugin-dirDirectory where plugins are installed
--portTCP/IP port number to use for connection
--print-defaultsPrint default options
--protocolConnection protocol to use
--shared-memory-base-nameThe name of shared memory to use for shared-memory connections
--skip-sys-schemaDo not install or upgrade the sys schema
--socketFor connections to localhost, the Unix socket file to use
--ssl-caPath of file that contains list of trusted SSL CAs
--ssl-capathPath of directory that contains trusted SSL CA certificates in PEM format
--ssl-certPath of file that contains X509 certificate in PEM format
--ssl-cipherList of permitted ciphers to use for connection encryption
--ssl-crlPath of file that contains certificate revocation lists
--ssl-crlpathPath of directory that contains certificate revocation list files
--ssl-keyPath of file that contains X509 key in PEM format
--ssl-modeSecurity state of connection to server
--tls-versionProtocols permitted for secure connections
--upgrade-system-tablesUpdate only system tables, not data
--userMySQL user name to use when connecting to server
--verboseVerbose mode
--version-checkCheck for proper server version
--write-binlogWrite all statements to binary log

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