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 2.19.4, “Rebuilding or Repairing Tables or Indexes” for manual table repair strategies.
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 2.19.1, “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 <
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
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 2.12, “Installing MySQL on Linux Using RPM Packages”.)
In MySQL 5.0.19, mysql_upgrade was added as a shell script and worked only for Unix systems. As of MySQL 5.0.25, 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] groups of an option file. 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 188.8.131.52, “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.
The path name of the directory to use for creating temporary files. This option was added in MySQL 5.0.62.
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.