Delete duplicate tuples from an entity that uses a pseudo primary key (eg, sequence/auto increment) instead of true keys

delete_duplicates.sql

--Make a temporary table for unneeded PKs
create temporary table dirty_identifier (pseudo_key integer);
-- Get the PKs we don't need
insert into dirty_identifier (
  select dt1.pseudo_pk from dirty_table as dt1, dirty_table as dt2 where
  dt1.true_pk_1 = dt2.true_pk_1
-- and dt1.true_pk_2 = dt2.true_pk_3
-- and ... keep repeating for however many attributes make your real key
  and dt1.pseudo_pk > dt2.pseudo_pk
);
-- Finally delete the unneeded tuples from the dirty table
delete from dirty_table where pseudo_pk in (select pseudo_pk from dirty_identifier);