Deleting duplicates rows from redshift

Question

I am trying to delete some duplicate data in my redshift table.

Below is my query:-

With duplicates
As
(Select *, ROW_NUMBER() Over (PARTITION by rec         


        

Answer 1

The following deletes all records in 'tablename' that have a duplicate, it will not deduplicate the table:

DELETE FROM tablename
WHERE id IN (
    SELECT id
    FROM (
          SELECT id,
          ROW_NUMBER() OVER (partition BY column1, column2, column3 ORDER BY id) AS rnum
          FROM tablename
         ) t
     WHERE t.rnum > 1);

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