インストール時にエラーが発生しました

[itsbhanusharma (Bhanu Sharma)]

There is an article about using external postgres which may fit your usecase.

Configure Discourse to use a separate PostgreSQL server

Let’s say you’re using AWS RDS, or an existing PostgreSQL server managed elsewhere. It’s fairly straightforward to get Discourse to use such a setup, without needing to grant superuser privileges to anything that Discourse itself runs. Here’s how. Prerequisites Discourse requires PostgreSQL’s major version to match what we ship with in our docker images; if you try to run on a newer or older version, it might work, but we don’t guarantee it, and if something breaks in the future, you get to …