不同的PostgreSQL时间戳可以相等吗？

Question

有时候，我会看到ORDER BY date, id。为什么需要id？

两个不同时期如何平等？

timestamp的精确度是多少？

Answer 1

你问过＆＃34; ORDER BY date，id。＆＃34;但随后提到时间戳。名为date的字段可能是时间戳类型或日期类似＆＃39; YYYY / MM / DD＆＃39;在这种情况下，按ID排序

Answer 2

Since timestamps are discrete values there can be multiple timestamps with the same value regardless of the precision. The bigger the precision the least likely is a collision. An untie criteria is necessary if that is relevant.