The Way to Update A Small RAM VPS

So I have a VPS with about 700MB RAM but the available is < 100MB. Today when I do

yum update

I got the error saying

xxxx: [Errno 5] [Errno 12] Cannot allocate memory

So I solved this by update everything one by one using the following command:

for item in $(yum list updates | tail -n+8 |awk '{print $1}'); do sudo yum update $item -y; done

The solution comes from https://commandlinelog.wordpress.com/2014/09/28/yum-update-on-low-ram/.