If you want to delete duplicate records then you can use this query.
BY Best Interview Question ON 05 Jun 2020

Example

Select rowNumber FROM tableName
WHERE rowNumber  
       IN (SELECT rowNumber
             FROM (SELECT rowNumber  
                        , ROWNUMBER() OVER(PARTITION BY c1,c2,c3) dup
                     FROM tableName)
            WHERE dup> 1 )