安装postgres9.4
yum install -y https://download.postgresql.org/pub/repos/yum/9.4/redhat/rhel-7-x86_64/pgdg-centos94-9.4-3.noarch.rpm
yum install -y postgresql94-server postgresql94-contrib
/usr/pgsql-9.4/bin/postgresql94-setup initdb
systemctl enable postgresql-9.4.service
systemctl start postgresql-9.4.service
systemctl status postgresql-9.4.service