ALTER INDEX [schema.] index
{ { { deallocate_unused_clause | allocate_extent_clause }
  | parallel_clause
  | physical_attributes_clause
  | { LOGGING | NOLOGGING }
  } 
  [ { deallocate_unused_clause | allocate_extent_clause }
    | parallel_clause
    | physical_attributes_clause
    | { LOGGING | NOLOGGING }
  ]...
| rebuild_clause
| PARAMETERS ( 'alter_index_params' )
| { ENABLE | DISABLE }
| UNUSABLE
| RENAME [PARTITION partition] TO new_name
| COALESCE
| { MONITORING | NOMONITORING } USAGE
| UPDATE BLOCK REFERENCES
| alter_index_partitioning
}
;

For information on the symbols and conventions of Backus-Naur Form (BNF) syntax, see Appendix A.