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There are a number of ways using SQL statements to modify partitioned tables; it is possible to add, drop, redefine, merge, or split existing partitions using the partitioning extensions to theALTER TABLE statement. There are also ways to obtain information about partitioned tables and partitions. We discuss these topics in the sections that follow.

To change a table's partitioning scheme, it is necessary only to use theALTER TABLE statement with apartition_options option, which has the same syntax as that as used withCREATE TABLE for creating a partitioned table; this option (also) always begins with the keywordsPARTITION BY. Suppose that the followingCREATE TABLE statement was used to create a table that is partitioned by range:

CREATE TABLE trb3 (id INT, name VARCHAR(50), purchased DATE)    PARTITION BY RANGE( YEAR(purchased) ) (        PARTITION p0 VALUES LESS THAN (1990),        PARTITION p1 VALUES LESS THAN (1995),        PARTITION p2 VALUES LESS THAN (2000),        PARTITION p3 VALUES LESS THAN (2005)    );

To repartition this table so that it is partitioned by key into two partitions using theid column value as the basis for the key, you can use this statement:

ALTER TABLE trb3 PARTITION BY KEY(id) PARTITIONS 2;

This has the same effect on the structure of the table as dropping the table and re-creating it usingCREATE TABLE trb3 PARTITION BY KEY(id) PARTITIONS 2;.

ALTER TABLE ... ENGINE [=] ... changes only the storage engine used by the table, and leaves the table's partitioning scheme intact. The statement succeeds only if the target storage engine provides partitioning support. You can useALTER TABLE ... REMOVE PARTITIONING to remove a table's partitioning; seeSection 15.1.9, “ALTER TABLE Statement”.

You can delete all rows from one or more selected partitions usingALTER TABLE ... TRUNCATE PARTITION.