WITH indexes AS (SELECT 
  n.nspname AS sch,
  c2.relname AS tbl,
  c.relname AS indx,    
  array_agg(a.attname ORDER BY a.attnum) AS clm,
  EXISTS (SELECT * FROM pg_catalog.pg_constraint AS o WHERE o.conindid=i.indexrelid) AS is_constraint
FROM 
  pg_catalog.pg_class AS c INNER JOIN pg_catalog.pg_index AS i ON i.indexrelid = c.oid
  INNER JOIN pg_catalog.pg_class AS c2  ON i.indrelid = c2.oid
  INNER JOIN pg_catalog.pg_namespace AS n ON c.relnamespace = n.oid
  INNER JOIN pg_catalog.pg_authid AS u ON  n.nspowner = u.oid
  INNER JOIN pg_catalog.pg_attribute AS a ON a.attrelid = c.oid    
WHERE c.relkind = 'i'
AND i.indisunique=TRUE
AND a.attnum>=1
AND a.attisdropped = FALSE
AND (n.nspname = 'public'
	 OR u.rolname <> 'postgres')
GROUP BY n.nspname, c2.relname, c.relname, i.indisunique, is_constraint),
duplicates AS (SELECT A.sch AS table_schema, A.tbl AS table_name, A.is_constraint AS is_idx1_constraint, A.indx AS idx1, A.clm AS idx1_columns,
B.clm AS idx2_columns, B.is_constraint AS is_idx2_constraint, B.indx AS idx2
FROM indexes AS A, indexes AS B
WHERE A.sch=B.sch AND A.tbl=B.tbl 
AND NOT (a.clm@>b.clm AND b.clm@>a.clm)
AND a.clm@>b.clm
AND NOT (A.is_constraint=TRUE AND B.is_constraint=TRUE))
SELECT format('DROP INDEX %1$I.%2$I;', table_schema, idx1) AS statements
FROM duplicates
WHERE is_idx1_constraint=FALSE
UNION SELECT format('DROP INDEX %1$I.%2$I;', table_schema, idx2) AS statements
FROM duplicates
WHERE is_idx2_constraint=FALSE
ORDER BY statements;