to_char() 응답이 느릴떄(slow query)

Postgres SQL - to_char가 응답이 늦을떄(Slow Query)

원문

select to_char("Timestamp",'YYYY/MM/DD HH24:MI:SS') as "Timestamp" from xxx order by 1 asc

수정

select to_char("Timestamp",'YYYY/MM/DD HH24:MI:SS') as "Timestamp" from ( select "Timestamp" from xxx order by 1 asc )s

-- 변환 없이 쿼리를 하고, 원하는 포맷으로 감싸라 !!! ( 5배 빨라진다. )

참조 : https://stackoverflow.com/questions/24437023/postgresql-to-char-slowing-query-a-by-a-lot