Oracle : Identifying duplicates in a table without index
- by user288031
When I try to create a unique index on a large table, I get a unique contraint error. The unique index in this case is a composite key of 4 columns.
Is there an efficient way to identify the duplicates other than :
select col1, col2, col3, col4, count()
from Table1
group by col1, col2, col3, col4
having count() 1
The explain plan above shows full table scan with extremely high cost, and just want to find if there is another way.
Thanks !