TRUNCATE CLUSTER
TRUNCATE CLUSTER [schema
.]cluster_name
] [{DROP | REUSE} STORAGE]
Removes all rows from a cluster (cluster_name).
The cluster to be truncated must be in your schema, or you must have the DROP ANY TABLE privilege to truncate a cluster in another schema. The TRUNCATE command does not create rollback records, so it cannot be rolled back. This characteristic makes TRUNCATE extremely fast, and it is preferable to DELETE FROM unless the rollback capability is required. When a table is truncated and the DROP STORAGE clause is specified, only the initial extent of the table is retained; all other storage is deallocated.