在 14.04 安装时，postgresql 是通过安装
sudo apt-get install postgresql postgresql-contrib libpq-dev
此安装旨在成为从属设备，但如果不运行 pg_resetxlog，则无法启动。即使/usr/lib/postgresql/9.3/bin/有 pg_resetxlog，系统也需要安装“postgres-xc”。
apt-get install postgres-xc
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages …