You can redefine a partition by using the REORGANIZE PARTITION clause of the ALTER statement. By redefining partitions, you can combine multiple partitions into one or divide one into multiple.
ALTER {TABLE | CLASS} <table_name>
REORGANIZEPARTITION
<alter partition name comma list>
INTO ( <partition definition comma list> )
partition definition comma list:
PARTITION <partition_name> VALUES IN ( <partition_value_list>),...
The following example shows how to create the athlete2 table partitioned by the list of sport events, and redefine the event2 partition to be divided into event2_1 (Judo) and event2_2 (Taekwondo, Boxing).
CREATE TABLE athlete2( name VARCHAR(40), event VARCHAR(30) )
PARTITION BY LIST (event) (
PARTITION event1 VALUES IN ('Swimming', 'Athletics ' ),
PARTITION event2 VALUES IN ('Judo', 'Taekwondo','Boxing'),
PARTITION event3 VALUES IN ('Football', 'Basketball', 'Baseball')
);
ALTER TABLE athlete2 REORGANIZE PARTITION event2 INTO
(PARTITION event2_1 VALUES IN ('Judo'),
PARTITION event2_2 VALUES IN ( 'Taekwondo','Boxing'));
The following example shows how to combine the event2_1 and event2_2 partitions divided in Example 1 back into a single event2 partition.
ALTER TABLE athlete2 REORGANIZE PARTITION event2_1, event2_2 INTO
(PARTITION event2 VALUES IN('Judo','Taekwondo','Boxing'));