Server 9.x & docker Elastic Search

Hello, I’m running CE edition v 8 on a Banana PI (same hardware as raspberry), I’m reading the documentation to upgrade to version 9. I just wanted to know I understood it right: we need to install docker in order to upgrade to version 9? That’s because of elastic search, which should be mandatory, right?
I’m asking, because my little home arm server does not have much resources, basically it runs as a server, the web interface is not used, because is very slow. I’m afraid it will be overwhelmed if I add a containers on it.

The CE edition does not need Elastic Search.