If you upgrade to MariaDB 5.1 from MySQL 5.1 you [[how-can-i-upgrade-from-mysql-to-mariadb|don't have to do anything]] with your data or MySQL clients. Things should "just work".
When upgrading between different major versions of MariaDB or MySQL you need to
run the [[mysql_upgrade]] program to convert data that are incompatible between versions. This will also update your privilege tables in the mysql database to the latest format.
In almost all cases [[mysql_upgrade]] should be able to convert your tables, without you having to dump and restore your data.
After installing MariaDB, just do:
<<code>>
mysql_upgrade --verbose
<</code>>
If you want to run with a specific TCP/IP port do:
<<code>>
mysql_upgrade --host=127.0.0.1 --port=3308 --protocol=tcp
<</code>>
If you want to connect with a socket do:
<<code>>
mysql_upgrade --socket=127.0.0.1 --protocol=socket
<</code>>
To see other options, use [[mysql_upgrade|--help]].
"mysql_upgrade" reads the my.cnf sections [mysql_upgrade] and [client] for default values.
There are a variety of reasons tables need to be converted; they could be any of the following:
* The collation (sorting order) for an index column has changed
* A field type has changed storage format
** DECIMAL and VARCHAR changed format between MySQL 4.1 and MySQL 5.0
* An engine has a new storage format
** ARCHIVE changed storage format between 5.0 and 5.1
* The format for storing table names has changed
** In MySQL 5.1 table names are encoded so that the file names are identical on all computers. Old table names that contains forbidden file name characters will show up prefixed with #mysql50# in 'SHOW TABLES' until you convert them.
If you don't convert the tables, one of the following things may happen:
* You will get warnings in the error log every time you access a table with an invalid (old) file name.
* When searching on key values you may not find all rows
* You will get an error "ERROR 1459 (HY000): Table upgrade required" when accessing the table.
* You may get crashes
"mysql_upgrade" works by calling mysqlcheck with different options and running the "mysql_fix_privileges" script. If you have trouble with "mysql_upgrade", you can run these commands separately to get more information of what is going on.
Most of the things in the [[http://dev.mysql.com/doc/refman/5.1/en/upgrading.html|MySQL 5.1 manual]] section also applies to MariaDB.
The following differences exists between "mysql_upgrade" in MariaDB and MySQL (as of MariaDB 5.1.50):
* MariaDB will convert long table names properly.
* MariaDB will convert InnoDB tables (no need to do a dump/restore or ALTER TABLE).
* MariaDB will convert old archive tables to the new 5.1 format (note: new feature in testing).
* "mysql_upgrade --verbose" will run "mysqlcheck --verbose" so that you get more information of what is happening.
