I found this instruction on web but yum is not finding postgres
[root@hadoop1 ~]# yum -y install postgressql
Loaded plugins: fastestmirror, priorities, protectbase, refresh-packagekit, security
Setting up Install Process
Loading mirror speeds from cached hostfile
0 packages excluded due to repository protections
No package postgressql available.
Error: Nothing to do
[root@hadoop1 ~]#