网上发现一个 postgres 里 soft delete 的实现:
http://shuber.io/porting-activerecord-soft-delete-behavior-to-postgres/
配以强大的 ruby 和 rails 就比较炫了:
https://www.gapintelligence.com/blog/2016/soft-delete-with-postgres-and-activerecord