Some releases of MySQL introduce changes to the structure of
the system tables in the mysql database
to add new privileges or support new features. When you
update to a new version of MySQL, you should update your
system tables as well to make sure that their structure is
up to date. Otherwise, there might be capabilities that you
cannot take advantage of. First, make a backup of your
mysql database, and then use the
following procedure.
Note: As of MySQL 5.0.19, mysql_fix_privilege_tables is superseded by mysql_upgrade, which should be used instead. See Section 5.6.2, “mysql_upgrade — Check Tables for MySQL Upgrade”.
On Unix or Unix-like systems, update the system tables by running the mysql_fix_privilege_tables script:
shell> mysql_fix_privilege_tables
You must run this script while the server is running. It
attempts to connect to the server running on the local host
as root. If your root
account requires a password, indicate the password on the
command line like this:
shell>mysql_fix_privilege_tables --password=root_password
The mysql_fix_privilege_tables script
performs any actions necessary to convert your system tables
to the current format. You might see some Duplicate
column name warnings as it runs; you can ignore
them.
After running the script, stop the server and restart it.
On Windows systems, MySQL distributions include a
mysql_fix_privilege_tables.sql SQL
script that you can run using the mysql
client. For example, if your MySQL installation is located
at C:\Program Files\MySQL\MySQL Server
5.0, the commands look like this:
C:\>cd "C:\Program Files\MySQL\MySQL Server 5.0"C:\>bin\mysql -u root -p mysqlmysql>SOURCE scripts/mysql_fix_privilege_tables.sql
The mysql command will prompt you for the
root password; enter it when prompted.
If your installation is located in some other directory, adjust the pathnames appropriately.
As with the Unix procedure, you might see some
Duplicate column name warnings as
mysql processes the statements in the
mysql_fix_privilege_tables.sql script;
you can ignore them.
After running the script, stop the server and restart it.
mysql_upgrade should be executed each time you upgrade MySQL. It checks all tables in all databases for incompatibilities with the current version of MySQL Server. If a table is found to have a possible incompatibility, it is checked. If any problems are found, the table is repaired. mysql_upgrade also upgrades the system tables so that you can take advantage of new privileges or capabilities that might have been added.
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 if all tables have
been checked for this release so that table-checking can be
skipped. To ignore this file, use the
--force option.
To check and repair tables and to upgrade the system tables, mysql_upgrade executes the following commands:
mysqlcheck --check-upgrade --all-databases --auto-repair mysql_fix_privilege_tables
mysql_upgrade supersedes the older mysql_fix_privilege_tables script. In MySQL 5.0.19, mysql_upgrade was added as a shell script and worked only for Unix systems. As of MySQL 5.0.23, mysql_upgrade is an executable binary and is available on all systems. On systems older than those supporting mysql_upgrade, you can execute the mysqlcheck command manually, and then upgrade your system tables as described in Section 5.6.1, “mysql_fix_privilege_tables — Upgrade MySQL System Tables”.
For details about what is checked, see the description of
the FOR UPGRADE option of the
CHECK TABLE statement (see
Section 13.5.2.3, “CHECK TABLE Syntax”).
To use mysql_upgrade, make sure that the server is running, and then invoke it like this:
shell>mysql_upgrade [options]
mysql_upgrade reads options from the
command line and fromm the [mysqld] and
[mysql_upgrade] groups in option files.
It supports the following options:
-
Display a short help message and exit.
-
The path to the MySQL installation directory.
-
The path to the data directory.
-
Force execution of mysqlcheck even if mysql_upgrade has already been executed for the current version of MySQL. (In other words, this option causes the
mysql_upgrade.infofile to be ignored.) -
--user=user_name,-uuser_nameThe MySQL username to use when connecting to the server. The default username is
root. -
Verbose mode. Print more information about what the program does.
Other options are passed to mysqlcheck
and to mysql_fix_privilege_tables. For
example, it might be necessary to specify the
--password[=password]
option.