This chapter discusses MySQL's implementation of user-defined partitioning. You can determine whether your MySQL Server supports partitioning by means of a SHOW VARIABLES statement such as this one:

mysql> SHOW VARIABLES LIKE '%partition%';

+-------------------+-------+
| Variable_name     | Value |
+-------------------+-------+
| have_partitioning | YES   |
+-------------------+-------+
1 row in set (0.00 sec)

You can also check the output of the SHOW PLUGINS statement, as shown here:

mysql> SHOW PLUGINS;
+------------+----------+----------------+---------+---------+
| Name       | Status   | Type           | Library | License |
+------------+----------+----------------+---------+---------+
| binlog     | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| partition  | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| ARCHIVE    | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| BLACKHOLE  | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| CSV        | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| FEDERATED  | DISABLED | STORAGE ENGINE | NULL    | GPL     |
| MEMORY     | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| InnoDB     | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| MRG_MYISAM | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| MyISAM     | ACTIVE   | STORAGE ENGINE | NULL    | GPL     |
| ndbcluster | DISABLED | STORAGE ENGINE | NULL    | GPL     |
+------------+----------+----------------+---------+---------+
11 rows in set (0.00 sec)

In MySQL 5.1.5 and later, you can also check the INFORMATION_SCHEMA.PLUGINS table with a query similar to this one:

mysql> SELECT 
    ->     PLUGIN_NAME as Name, 
    ->     PLUGIN_VERSION as Version, 
    ->     PLUGIN_STATUS as Status 
    -> FROM INFORMATION_SCHEMA.PLUGINS 
    -> WHERE PLUGIN_TYPE='STORAGE ENGINE';
+--------------------+---------+--------+
| Name               | Version | Status |
+--------------------+---------+--------+
| binlog             | 1.0     | ACTIVE |
| CSV                | 1.0     | ACTIVE |
| MEMORY             | 1.0     | ACTIVE |
| MRG_MYISAM         | 1.0     | ACTIVE |
| MyISAM             | 1.0     | ACTIVE |
| PERFORMANCE_SCHEMA | 0.1     | ACTIVE |
| BLACKHOLE          | 1.0     | ACTIVE |
| ARCHIVE            | 3.0     | ACTIVE |
| InnoDB             | 5.6     | ACTIVE |
| partition          | 1.0     | ACTIVE |
+--------------------+---------+--------+
10 rows in set (0.00 sec)

Whichever of the preceding statements you employ, if you do not see the partition plugin listed with the value ACTIVE for the Status column in the output (shown in bold text in each of the examples just given), then your version of MySQL was not built with partitioning support.

MySQL 5.1 Community binaries provided by Oracle include partitioning support. For information about partitioning support offered in commercial MySQL Server binaries, see MySQL Enterprise Server 5.1 on the MySQL Web site at http://www.mysql.com/products/enterprise/server.html.

If you are compiling MySQL 5.1 from source, the build must be configured using --with-partition to enable partitioning. Using --with-plugins=max to configure the build includes this option automatically.

If your MySQL binary is built with partitioning support, nothing further needs to be done to enable it (for example, no special entries are required in your my.cnf file).

If you want to disable partitioning support, you can start the MySQL Server with the --skip-partition option, in which case the value of have_partitioning is DISABLED. When partitioning support is disabled, you can see any existing partitioned tables and drop them (although doing this is not advised), but you cannot otherwise manipulate them or access their data.

An introduction to partitioning and partitioning concepts may be found in Section 18.1, “Overview of Partitioning in MySQL”.

MySQL supports several types of partitioning, which are discussed in Section 18.2, “Partitioning Types”, as well as subpartitioning, which is described in Section 18.2.5, “Subpartitioning”.

Methods of adding, removing, and altering partitions in existing partitioned tables are covered in Section 18.3, “Partition Management”.

Table maintenance commands for use with partitioned tables are discussed in Section 18.3.3, “Maintenance of Partitions”.

Beginning with MySQL 5.1.6, the PARTITIONS table in the INFORMATION_SCHEMA database provides information about partitions and partitioned tables. See Section 20.11, “The INFORMATION_SCHEMA PARTITIONS Table”, for more information; for some examples of queries against this table, see Section 18.2.6, “How MySQL Partitioning Handles NULL”.

For known issues with partitioning in MySQL 5.1, see Section 18.5, “Restrictions and Limitations on Partitioning”.

You may also find the following resources to be useful when working with partitioned tables.

Additional Resources.  Other sources of information about user-defined partitioning in MySQL include the following:

MySQL 5.1 binaries are available from http://dev.mysql.com/downloads/mysql/5.1.html. However, for the latest partitioning bugfixes and feature additions, you can obtain the source from our Bazaar repository. To enable partitioning, you need to compile the server using the --with-partition option. For more information about building MySQL, see Section 2.11, “Installing MySQL from Source”. If you have problems compiling a partitioning-enabled MySQL 5.1 build, check the MySQL Partitioning Forum and ask for assistance there if you do not find a solution to your problem already posted.