Merge Partitions

Use alter table ... merge partition to combine the data from two or more merge-compatible (that is, available for the merge) partitions into a single partition.

Whether partitions are merge compatible depends on how they are partitioned:
The syntax is:
alter table table_name 
merge partition  {partition_name  [{, partition_name}…]} 
into destination_partition_name [on segment_name]

See Reference Manual: Commands.

You must enable select into/bulkcopy to issue alter table ... merge partition.

alter table ... merge partition is fully logged. Use the transaction dump to recover from a server failure.

This example creates the sales table and then merges its partitions to consolidate the data:
create table sales(salesmanid int, salesdate datetime, salesregion varchar(10))
partition by range(salesdate)
( Q1 values <= ('31 Mar 2007'),
  Q2 values <= ('30 Jun 2007'),
  Q3 values <= ('30 Sep 2007'),
  Q4 values <= ('31 Dec 2007'))
create index ind_region on sales(salesregion)

alter table sales
merge partition Q3
into Q4

alter table sales
merge partition Q1, Q2, Q3, Q4 
into Y2007