ALTER CLUSTER [schema .] cluster
{ physical_attributes_clause
| SIZE integer [ K | M ]
| allocate_extent_clause
| deallocate_unused_clause
| {CACHE | NOCACHE}
}
[ physical_attributes_clause
| SIZE integer [ K | M ]
| allocate_extent_clause
| deallocate_unused_clause
| {CACHE | NOCACHE}
]...
[parallel_clause]
;