MYSQL_UPGRADE

Section: MySQL Database System (1)
Updated: 12/11/2025
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NAME

mysql_upgrade - check and upgrade MySQL tables  

SYNOPSIS

mysql_upgrade [options]

 

DESCRIPTION

Note

As of MySQL 8.0.16, the MySQL server performs the upgrade tasks previously handled by mysql_upgrade (for details, see Section 3.4, lqWhat the MySQL Upgrade Process Upgradesrq). Consequently, mysql_upgrade is unneeded and is deprecated as of that version; expect it to be removed in a future version of MySQL. Because mysql_upgrade no longer performs upgrade tasks, it exits with status 0 unconditionally.

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

* It upgrades the system tables in the mysql schema so that you can take advantage of new privileges or capabilities that might have been added.

* It upgrades the Performance Schema, INFORMATION_SCHEMA, and sys schema.

* It examines user schemas.

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 3.14, lqRebuilding or Repairing Tables or Indexesrq for manual table repair strategies.

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

Caution

You should always back up your current MySQL installation before performing an upgrade. See Section 9.2, lqDatabase Backup Methodsrq.

Some upgrade incompatibilities may require special handling before upgrading your MySQL installation and running mysql_upgrade. See Chapter 3, 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]

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

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 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:

$> 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:

$> mysql_upgrade [options]

Note

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 15.7.3.2, lqCHECK TABLE Statementrq.

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.

mysql_upgrade 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.

Note

The mysql_upgrade_info file is deprecated; expect it to be removed in a future version of MySQL.

mysql_upgrade checks mysql.user system 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 time zone tables or help tables. For upgrade instructions, see Section 7.1.15, lqMySQL Server Time Zone Supportrq, and Section 7.1.17, lqServe-Side Help Supportrq.

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.

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

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 6.2.2.2, lqUsing Option Filesrq.

* --help

Comman-Line Format

-help

Display a short help message and exit.

* --bind-address=ip_address

Comman-Line Format

-bin-address=ip_address

On a computer having multiple network interfaces, use this option to select which interface to use for connecting to the MySQL server.

* --character-sets-dir=dir_name

Comman-Line Format	-characte-set-dir=dir_name
Type	Directory name

The directory where character sets are installed. See Section 12.15, lqCharacter Set Configurationrq.

* --compress, -C

Comman-Line Format	-compress[={OFF|ON}]
Deprecated	8.0.18
Type	Boolean
Default Value	OFF

Compress all information sent between the client and the server if possible. See Section 6.2.8, lqConnection Compression Controlrq.

As of MySQL 8.0.18, this option is deprecated. Expect it to be removed in a future version of MySQL. See the section called lqConfiguring Legacy Connection Compressionrq.

* --compression-algorithms=value

Comman-Line Format	-compressio-algorithms=value
Introduced	8.0.18
Type	Set
Default Value	uncompressed
Valid Values	zlib zstd uncompressed

The permitted compression algorithms for connections to the server. The available algorithms are the same as for the protocol_compression_algorithms system variable. The default value is uncompressed.

For more information, see Section 6.2.8, lqConnection Compression Controlrq.

This option was added in MySQL 8.0.18.

* --debug[=debug_options], -# [debug_options]

Comman-Line Format	-debug[=#]
Type	String
Default Value	d:t:O,/tmp/mysql_upgrade.trace

Write a debugging log. A typical debug_options string is d:t:o,file_name. The default is d:t:O,/tmp/mysql_upgrade.trace.

* --debug-check

Comman-Line Format	-debu-check
Type	Boolean

Print some debugging information when the program exits.

* --debug-info, -T

Comman-Line Format	-debu-info
Type	Boolean
Default Value	FALSE

Print debugging information and memory and CPU usage statistics when the program exits.

* --default-auth=plugin

Comman-Line Format	-defaul-auth=plugin
Type	String

A hint about which client-side authentication plugin to use. See Section 8.2.17, lqPluggable Authenticationrq.

* --default-character-set=charset_name

Comman-Line Format	-defaul-characte-set=name
Type	String

Use charset_name as the default character set. See Section 12.15, lqCharacter Set Configurationrq.

* --defaults-extra-file=file_name

Comman-Line Format	-default-extr-file=file_name
Type	File name

Read this option file after the global option file but (on Unix) before the user option file. If the file does not exist or is otherwise inaccessible, an error occurs. If file_name is not an absolute path name, it is interpreted relative to the current directory.

For additional information about this and other option-file options, see Section 6.2.2.3, lqComman-Line Options that Affect Optio-File Handlingrq.

* --defaults-file=file_name

Comman-Line Format	-default-file=file_name
Type	File name

Use only the given option file. If the file does not exist or is otherwise inaccessible, an error occurs. If file_name is not an absolute path name, it is interpreted relative to the current directory.

For additional information about this and other option-file options, see Section 6.2.2.3, lqComman-Line Options that Affect Optio-File Handlingrq.

* --defaults-group-suffix=str

Comman-Line Format	-default-grou-suffix=str
Type	String

Read not only the usual option groups, but also groups with the usual names and a suffix of str. For example, mysql_upgrade normally reads the [client] and [mysql_upgrade] groups. If this option is given as --defaults-group-suffix=_other, mysql_upgrade also reads the [client_other] and [mysql_upgrade_other] groups.

For additional information about this and other option-file options, see Section 6.2.2.3, lqComman-Line Options that Affect Optio-File Handlingrq.

* --force

Comman-Line Format	-force
Type	Boolean

Ignore the mysql_upgrade_info file and force execution even if mysql_upgrade has already been executed for the current version of MySQL.

* --get-server-public-key

Comman-Line Format	-ge-serve-publi-key
Type	Boolean

Request from the server the public key required for RSA key pair-based password exchange. This option applies to clients that authenticate with the caching_sha2_password authentication plugin. For that plugin, the server does not send the public key unless requested. This option is ignored for accounts that do not authenticate with that plugin. It is also ignored if RSA-based password exchange is not used, as is the case when the client connects to the server using a secure connection.

If --server-public-key-path=file_name is given and specifies a valid public key file, it takes precedence over --get-server-public-key.

For information about the caching_sha2_password plugin, see Section 8.4.1.2, lqCaching SH-2 Pluggable Authenticationrq.

* --host=host_name, -h host_name

Comman-Line Format	-host=name
Type	String

Connect to the MySQL server on the given host.

* --login-path=name

Comman-Line Format	-logi-path=name
Type	String

Read options from the named login path in the .mylogin.cnf login path file. A lqlogin pathrq is an option group containing options that specify which MySQL server to connect to and which account to authenticate as. To create or modify a login path file, use the mysql_config_editor utility. See mysql_config_editor(1).

For additional information about this and other option-file options, see Section 6.2.2.3, lqComman-Line Options that Affect Optio-File Handlingrq.

* --max-allowed-packet=value

Comman-Line Format	-ma-allowe-packet=value
Type	Integer
Default Value	25165824
Minimum Value	4096
Maximum Value	2147483648

The maximum size of the buffer for client/server communication. The default value is 24MB. The minimum and maximum values are 4KB and 2GB.

* --net-buffer-length=value

Comman-Line Format	-ne-buffe-length=value
Type	Integer
Default Value	1047552
Minimum Value	4096
Maximum Value	16777216

The initial size of the buffer for client/server communication. The default value is 1MB − 1KB. The minimum and maximum values are 4KB and 16MB.

* --no-defaults

Comman-Line Format

-n-defaults

Do not read any option files. If program startup fails due to reading unknown options from an option file, --no-defaults can be used to prevent them from being read.

The exception is that the .mylogin.cnf file is read in all cases, if it exists. This permits passwords to be specified in a safer way than on the command line even when --no-defaults is used. To create .mylogin.cnf, use the mysql_config_editor utility. See mysql_config_editor(1).

For additional information about this and other option-file options, see Section 6.2.2.3, lqComman-Line Options that Affect Optio-File Handlingrq.

* --password[=password], -p[password]

Comman-Line Format	-password[=name]
Type	String

The password of the MySQL account used for connecting to the server. The password value is optional. If not given, mysql_upgrade prompts for one. If given, there must be no space between --password= or -p and the password following it. If no password option is specified, the default is to send no password.

Specifying a password on the command line should be considered insecure. To avoid giving the password on the command line, use an option file. See Section 8.1.2.1, lqEn-User Guidelines for Password Securityrq.

To explicitly specify that there is no password and that mysql_upgrade should not prompt for one, use the --skip-password option.

* --pipe, -W

Comman-Line Format	-pipe
Type	String

On Windows, connect to the server using a named pipe. This option applies only if the server was started with the named_pipe system variable enabled to support named-pipe connections. In addition, the user making the connection must be a member of the Windows group specified by the named_pipe_full_access_group system variable.

* --plugin-dir=dir_name

Comman-Line Format	-plugi-dir=dir_name
Type	Directory name

The directory in which to look for plugins. Specify this option if the --default-auth option is used to specify an authentication plugin but mysql_upgrade does not find it. See Section 8.2.17, lqPluggable Authenticationrq.

* --port=port_num, -P port_num

Comman-Line Format	-port=#
Type	Numeric

For TCP/IP connections, the port number to use.

* --print-defaults

Comman-Line Format

-prin-defaults

Print the program name and all options that it gets from option files.

* --protocol={TCP|SOCKET|PIPE|MEMORY}

Comman-Line Format	-protocol=name
Type	String

The transport protocol to use for connecting to the server. It is useful when the other connection parameters normally result in use of a protocol other than the one you want. For details on the permissible values, see Section 6.2.7, lqConnection Transport Protocolsrq.

* --server-public-key-path=file_name

Comman-Line Format	-serve-publi-ke-path=file_name
Type	File name

The path name to a file in PEM format containing a client-side copy of the public key required by the server for RSA key pair-based password exchange. This option applies to clients that authenticate with the sha256_password or caching_sha2_password authentication plugin. This option is ignored for accounts that do not authenticate with one of those plugins. It is also ignored if RSA-based password exchange is not used, as is the case when the client connects to the server using a secure connection.

If --server-public-key-path=file_name is given and specifies a valid public key file, it takes precedence over --get-server-public-key.

For sha256_password, this option applies only if MySQL was built using OpenSSL.

For information about the sha256_password and caching_sha2_password plugins, see Section 8.4.1.3, lqSH-256 Pluggable Authenticationrq, and Section 8.4.1.2, lqCaching SH-2 Pluggable Authenticationrq.

* --shared-memory-base-name=name

Comman-Line Format	-share-memor-bas-name=name
Platform Specific	Windows

On Windows, the shared-memory name to use for connections made using shared memory to a local server. The default value is MYSQL. The shared-memory name is case-sensitive.

This option applies only if the server was started with the shared_memory system variable enabled to support shared-memory connections.

* --skip-sys-schema

Comman-Line Format	-ski-sy-schema
Type	Boolean
Default Value	FALSE

By default, mysql_upgrade installs the sys schema if it is not installed, and upgrades it to the current version otherwise. The --skip-sys-schema option suppresses this behavior.

* --socket=path, -S path

Comman-Line Format	-socket={file_name|pipe_name}
Type	String

For connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use.

On Windows, this option applies only if the server was started with the named_pipe system variable enabled to support named-pipe connections. In addition, the user making the connection must be a member of the Windows group specified by the named_pipe_full_access_group system variable.

* --ssl* Options that begin with --ssl specify whether to connect to the server using encryption and indicate where to find SSL keys and certificates. See the section called lqCommand Options for Encrypted Connectionsrq.

* --ssl-fips-mode={OFF|ON|STRICT}

Comman-Line Format	-ss-fip-mode={OFF|ON|STRICT}
Deprecated	8.0.34
Type	Enumeration
Default Value	OFF
Valid Values	OFF ON STRICT

Controls whether to enable FIPS mode on the client side. The --ssl-fips-mode option differs from other --ssl-xxx options in that it is not used to establish encrypted connections, but rather to affect which cryptographic operations to permit. See Section 8.8, lqFIPS Supportrq.

These --ssl-fips-mode values are permitted:

* OFF: Disable FIPS mode.

* ON: Enable FIPS mode.

* STRICT: Enable lqstrictrq FIPS mode.

Note
If the OpenSSL FIPS Object Module is not available, the only permitted value for --ssl-fips-mode is OFF. In this case, setting --ssl-fips-mode to ON or STRICT causes the client to produce a warning at startup and to operate in non-FIPS mode.

As of MySQL 8.0.34, this option is deprecated. Expect it to be removed in a future version of MySQL.

* --tls-ciphersuites=ciphersuite_list

Comman-Line Format	-tl-ciphersuites=ciphersuite_list
Introduced	8.0.16
Type	String

The permissible ciphersuites for encrypted connections that use TLSv1.3. The value is a list of one or more colon-separated ciphersuite names. The ciphersuites that can be named for this option depend on the SSL library used to compile MySQL. For details, see Section 8.3.2, lqEncrypted Connection TLS Protocols and Ciphersrq.

This option was added in MySQL 8.0.16.

* --tls-version=protocol_list

Comman-Line Format	-tl-version=protocol_list
Type	String
Default Value (≥ 8.0.16)	TLSv1,TLSv1.1,TLSv1.2,TLSv1.3 (OpenSSL 1.1.1 or higher) TLSv1,TLSv1.1,TLSv1.2 (otherwise)
Default Value (≤ 8.0.15)	TLSv1,TLSv1.1,TLSv1.2

The permissible TLS protocols for encrypted connections. The value is a list of one or more comma-separated protocol names. The protocols that can be named for this option depend on the SSL library used to compile MySQL. For details, see Section 8.3.2, lqEncrypted Connection TLS Protocols and Ciphersrq.

* --upgrade-system-tables, -s

Comman-Line Format	-upgrad-syste-tables
Type	Boolean

Upgrade only the system tables in the mysql schema, do not upgrade user schemas.

* --user=user_name, -u user_name

Comman-Line Format	-user=name
Type	String

The user name of the MySQL account to use for connecting to the server. The default user name is root.

* --verbose

Comman-Line Format	-verbose
Type	Boolean

Verbose mode. Print more information about what the program does.

* --version-check, -k

Comman-Line Format	-versio-check
Type	Boolean

Check the version of the server to which mysql_upgrade is connecting to verify that it is the same as the version for which mysql_upgrade was built. If not, mysql_upgrade exits. This option is enabled by default; to disable the check, use --skip-version-check.

* --write-binlog

Comman-Line Format	-writ-binlog
Type	Boolean
Default Value	OFF

By default, binary logging by mysql_upgrade is disabled. Invoke the program with --write-binlog if you want its actions to be written to the binary log.

When the server is running with global transaction identifiers (GTIDs) enabled (gtid_mode=ON), do not enable binary logging by mysql_upgrade.

* --zstd-compression-level=level

Comman-Line Format	-zst-compressio-level=#
Introduced	8.0.18
Type	Integer

The compression level to use for connections to the server that use the zstd compression algorithm. The permitted levels are from 1 to 22, with larger values indicating increasing levels of compression. The default zstd compression level is 3. The compression level setting has no effect on connections that do not use zstd compression.

For more information, see Section 6.2.8, lqConnection Compression Controlrq.

This option was added in MySQL 8.0.18.

 

COPYRIGHT

Copyright © 1997, 2025, Oracle and/or its affiliates.

This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License.

This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with the program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 0211-1301 USA or see http://www.gnu.org/licenses/.

 

SEE ALSO

For more information, please refer to the MySQL Reference Manual, which may already be installed locally and which is also available online at http://dev.mysql.com/doc/.  

AUTHOR

Oracle Corporation (http://dev.mysql.com/).

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Index

NAME

SYNOPSIS

DESCRIPTION

COPYRIGHT

SEE ALSO

AUTHOR