We released pg_power gem which extends ActiveRecord and allows to use PostreSQL's power:)
http://greyblake.com/blog/2012/09/06/pg-power-activerecord-extension-for-postgresql/
-- Sergey
P.S. Sorry for English. Unfortunately I don't know Chinese, but I noted that a lot of people come to my blog via ruby-china.
Welcome to ruby-china! ( unofficially : ) ) Feel free to post the valuable links or words in english here ,i guess most of rubyists can understand them well, meanwhile Google translation will be a help, sometimes the codes itself can tell everything , i believe there must be more rubyists to visit your blog ~ Thx for your sharing ~
#8 楼 @hooopo 用 RDBMS，没特别的理由，都该加上外键约束才对的啊。
毕竟是 RDBMS 啊。
http://stackoverflow.com/questions/83147/whats-wrong-with-foreign-keys