Detecting duplicate Oracle indexes

轉自:http://www.dba-oracle.com/t_detecting_duplicate_indexes.htm

真的很神奇的SQL。

select /*+ rule */
   a.table_owner,
   a.table_name,
   a.index_owner,
   a.index_name,
   column_name_list,
   column_name_list_dup,
   dup duplicate_indexes,
   i.uniqueness,
   i.partitioned,
   i.leaf_blocks,
   i.distinct_keys,
   i.num_rows,
   i.clustering_factor
from
  (
   select
      table_owner,
      table_name,
      index_owner,
      index_name,
      column_name_list_dup,
      dup,
      max(dup) OVER
       (partition by table_owner, table_name,
index_name) dup_mx
   from
      (
       select
          table_owner,
          table_name,
          index_owner,
          index_name,
         
substr(SYS_CONNECT_BY_PATH(column_name, ','),2)  
          column_name_list_dup,
          dup
       from
          (
          select
            index_owner,

            index_name,

            table_owner,

            table_name,

            column_name,

            count(1) OVER

            
(partition by
                
index_owner,
                
index_name) cnt,
            
ROW_NUMBER () OVER
              
(partition by
                 
index_owner,
                 
index_name
               
order by column_position) as seq,
            
count(1) OVER
              
(partition by
                 
table_owner,
                 
table_name,
                 
column_name,
                 
column_position) as dup
   from
      sys.dba_ind_columns
   where
      index_owner not in ('SYS', 'SYSTEM','DLOBAUGH')

)
where
   dup!=1
start with seq=1
connect by prior seq+1=seq
and prior index_owner=index_owner
and prior index_name=index_name
)) a,
(
select
   table_owner,
   table_name,
   index_owner,
   index_name,
   substr(SYS_CONNECT_BY_PATH(column_name, ','),2) column_name_list

from
(
select index_owner, index_name, table_owner, table_name, column_name,
count(1) OVER ( partition by index_owner, index_name) cnt,
ROW_NUMBER () OVER ( partition by index_owner, index_name order by
column_position) as seq
from sys.dba_ind_columns
where index_owner not in ('SYS', 'SYSTEM'))
where seq=cnt
start with seq=1
connect by prior seq+1=seq
and prior index_owner=index_owner
and prior index_name=index_name
) b, dba_indexes i
where
    a.dup=a.dup_mx
and a.index_owner=b.index_owner
and a.index_name=b.index_name
and a.index_owner=i.owner
and a.index_name=i.index_name
order by
   a.table_owner, a.table_name, column_name_list_dup;