Reducing the Size of a Tablespace
The size of a tablespace is reduced by reorganizing all the tables in the tablespace and then backing up the tablespace and restoring it while redefining the physical layout.
To reorganize the tables, you use the DBA Planning Calendar, scheduling the "Reorg. Tables in Tablespace(s)" job (see Reorganizing a Tablespace).
You back up the tablespace using the DB2 Control Center.
When you restore the tablespace, you redefine the container layout. You can either remove containers, change the size of containers or do both simultaneously.
For a detailed description of the database and tablespace restore process, refer to the DB2 Control Center online help.