can the source document be a db path or elastic path

[ravindranantony]

how can I point the source documents to a DB or a URL

[johnbrisbin]

Without adding code, their is no support for either of those things. For now you will need to export the data to a local file(s) or download same.
As you probably noticed, this is a very new project and 'experimental', which is to say rough around the edges and lacking in many features that it might ultimately have.