The contents of two adjacent interval partitions can be merged into one partition. Nonadjacent interval partitions cannot be merged. The first interval partition can also be merged with the highest range partition. The resulting partition inherits the higher upper bound of the two merged partitions.
Merging interval partitions always results in the transition point being moved to the higher upper bound of the two merged partitions. This result is that the range section of the interval-partitioned table is extended to the upper bound of the two merged partitions. Any materialized interval partitions with boundaries lower than the newly merged partition are automatically converted into range partitions, with their upper boundaries defined by the upper boundaries of their intervals.
For example, consider the following interval-partitioned table transactions:
CREATE TABLE transactions ( id NUMBER , transaction_date DATE , value NUMBER ) PARTITION BY RANGE (transaction_date) INTERVAL (NUMTODSINTERVAL(1,'DAY')) ( PARTITION p_before_2007 VALUES LESS THAN (TO_DATE('01-JAN-2007','dd-MON-yyyy')));
Inserting data into the interval section of the table creates the interval partitions for these days. The data for January 15, 2007 and January 16, 2007 are stored in adjacent interval partitions.
INSERT INTO transactions VALUES (1,TO_DATE('15-JAN-2007','dd-MON-yyyy'),100); INSERT INTO transactions VALUES (2,TO_DATE('16-JAN-2007','dd-MON-yyyy'),600); INSERT INTO transactions VALUES (3,TO_DATE('30-JAN-2007','dd-MON-yyyy'),200);
Next, merge the two adjacent interval partitions. The new partition again has a system-generated name.
ALTER TABLE transactions MERGE PARTITIONS FOR(TO_DATE('15-JAN-2007','dd-MON-yyyy')) , FOR(TO_DATE('16-JAN-2007','dd-MON-yyyy'));
The transition point for the
transactions table has now moved to January 17, 2007. The range section of the interval-partitioned table contains two range partitions: values less than January 1, 2007 and values less than January 17, 2007. Values greater than January 17, 2007 fall in the interval portion of the interval-partitioned table.