文章来源：http://blog.csdn.net/qq_26656329/article/details/78562310

• 删除相关的安装

sudo apt-get --purge remove postgresql\*

• 删除配置及文相关件

sudo rm -r /etc/postgresql/
sudo rm -r /etc/postgresql-common/
sudo rm -r /var/lib/postgresql/

• 删除用户和所在组

sudo userdel -r postgres
sudo groupdel postgres

• 重新安装

sudo apt-get install postgresql

参考https://stackoverflow.com/questions/2748607/how-to-thoroughly-purge-and-reinstall-postgresql-on-ubuntu