ALTER INDEX [schema.] index { { { deallocate_unused_clause | allocate_extent_clause } | parallel_clause | physical_attributes_clause | logging_clause } [ { deallocate_unused_clause | allocate_extent_clause } | parallel_clause | physical_attributes_clause | logging_clause ]... | 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 } ;