When you merge list partitions, the partitions being merged can be any two partitions. They do not need to be adjacent, as for range partitions, because list partitioning does not assume any order for partitions. The resulting partition consists of all of the data from the original two partitions. If you merge a default list partition with any other partition, then the resulting partition is the default partition.
The following statement merges two partitions of a table partitioned using the list method into a partition that inherits all of its attributes from the table-level default attributes.
MAXEXTENTS is specified in the statement.
ALTER TABLE q1_sales_by_region MERGE PARTITIONS q1_northcentral, q1_southcentral INTO PARTITION q1_central STORAGE(MAXEXTENTS 20);
The value lists for the two original partitions were specified as:
PARTITION q1_northcentral VALUES ('SD','WI') PARTITION q1_southcentral VALUES ('OK','TX')
sales_west partition value list comprises the set that represents the union of these two partition value lists, or specifically: