info: "See the Technical Writers assigned to Development Guidelines: https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments-to-development-guidelines"
The syntax of [GitLabs database](https://docs.gitlab.com/omnibus/settings/database.html)
configuration located in `database.yml` is changing and the legacy format is deprecated. The legacy format
supported using a single PostgreSQL adapter, whereas the new format is changing to support multiple databases. The `main:` database needs to be defined as a first configuration item.
This deprecation mainly impacts users compiling GitLab from source because Omnibus will handle this configuration automatically.