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 a table is found to have a possible incompatibility, mysql_upgrade performs a table check. If any problems are found, a table repair is attempted. If the table cannot be repaired, see Section 2.4.4, “Rebuilding or Repairing Tables or Indexes” for manual table repair strategies.
On Windows Server 2008 and Windows Vista, 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 6.2, “Database Backup Methods”.
Some upgrade incompatibilities may require special handling before you upgrade your MySQL installation and run mysql_upgrade. See Section 2.4.1, “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, and then invoke it like this:
After running mysql_upgrade, stop the server and restart it so that any changes made to the system tables take effect.
mysql_upgrade executes the following commands to check and repair tables and to upgrade the system tables:
mysqlcheck --all-databases --check-upgrade --auto-repair mysql <
fix_priv_tablesmysqlcheck --all-databases --check-upgrade --fix-db-names --fix-table-names
Notes about the preceding commands:
Because mysql_upgrade invokes
mysqlcheck with the
it 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.
fix_priv_tables represents a
script generated internally by
mysql_upgrade that contains SQL
statements to upgrade the tables in the
Prior to MySQL 5.1.31, mysql_upgrade does
not run the second mysqlcheck command,
which is necessary to re-encode database or table names that
contain nonalphanumeric characters. (They still appear after
the upgrade with the
described in Section 8.2.3, “Mapping of Identifiers to File Names”.) If you
have such database or table names, execute the second
mysqlcheck command manually after
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
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
If you install MySQL from RPM packages on Linux, you must install the server and client RPMs. mysql_upgrade is included in the server RPM but requires the client RPM because the latter includes mysqlcheck. (See Section 2.6.1, “Installing MySQL from RPM Packages on Linux”.)
In MySQL 5.1.7, mysql_upgrade was added as a shell script and worked only for Unix systems. As of MySQL 5.1.10, mysql_upgrade is an executable binary and is available on all systems.
mysql_upgrade supports the following options,
which can be specified on the command line or in the
[client] option file groups. Other options
are passed to mysqlcheck. For example, it
might be necessary to specify the
option. mysql_upgrade also supports the
options for processing option files described at
Section 22.214.171.124.1, “Command-Line Options that Affect Option-File Handling”.
Display a short help message and exit.
The path to the MySQL installation directory. This option is accepted for backward compatibility but ignored.
The path to the data directory. This option is accepted for backward compatibility but ignored.
Print some debugging information when the program exits. This option was added in MySQL 5.1.21.
Print debugging information and memory and CPU usage statistics when the program exits. This option was added in MySQL 5.1.21.
The path name of the directory to use for creating temporary files. This option was added in MySQL 5.1.25.
The MySQL user name to use when connecting to the server.
The default user name is
Verbose mode. Print more information about what the program does.
Cause binary logging to be enabled while
mysql_upgrade runs. This is the default
behavior; to disable binary logging during the upgrade, use
the inverse of this option (that is, start the program with
This option was introduced in MySQL 5.1.40.