oracle to see where the index table space and index rebuild

select index_name,tablespace_name from dba_indexes where index_name='INDEX_PS';

mobile

alter index INDEX_PS rebuild tablespace product;

The index INDF5 analyze
analyze index INDF5 validate structure;

INDF5 obtain statistical information from the view INDEX_STATS

select height,(del_lf_rows_len/lf_rows_len)*100 from index_stats where name='INDF5';

Reconstruction based on
(del_lf_rows_len / lf_rows_len) * 100 value greater than 20
the value of height greater than 4 (explain too many hierarchical binary tree)

If the above two cases, we need to consider rebuilding the index

alter index INDF5 rebuild;