find duplicates postgresql and mysql

pgsql:

SELECT t.id,t.name,t.type,t.content,t2.id,t2.name,t2.type,t2.content FROM records as t, records as t2 WHERE t.name = t2.name AND t.type = 'NS' AND t2.type = 'NS' AND t.content = t2.content AND t.id < t2.id limit 10;

mysql:

SELECT domain_id,name,type,content, count( * ) cnt FROM  records GROUP BY type HAVING cnt >1 ORDER BY cnt DESC LIMIT 100";