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;