You split a range or a materialized interval partition using the
ALTER TABLE SPLIT PARTITION statement in an interval-partitioned table. Splitting a range partition in the interval-partitioned table is described in "Splitting a Partition of a Range-Partitioned Table".
To split a materialized interval partition, you specify a value of the partitioning key column within the interval partition at which to split the partition. The first of the resulting two new partitions includes all rows in the original partition whose partitioning key column values map lower than the specified value. The second partition contains all rows whose partitioning key column values map greater than or equal to the specified value. The split partition operation moves the transition point up to the higher boundary of the partition you just split, and all materialized interval partitions lower than the newly split partitions are implicitly converted into range partitions, with their upper boundaries defined by the upper boundaries of the intervals.
You can optionally specify new attributes for the two range partitions resulting from the split. If there are local indexes defined on the table, then this statement also splits the matching partition in each local index. You cannot split interval partitions that have not yet been created.
The following example shows splitting the May 2007 partition in the monthly interval partitioned table
ALTER TABLE transactions SPLIT PARTITION FOR(TO_DATE('01-MAY-2007','dd-MON-yyyy')) AT (TO_DATE('15-MAY-2007','dd-MON-yyyy'));