It would be really useful to document here or in an extra page which possibilities there are for saving resources like images. Edwin has documented in his private blog a good description of how to store everything in the DB.
http://www.edwinology.com/2020/05/trying-out-docker-magnolia-and-postgres.html
This part is completely missing in the documentation. It would also be good to have a description of the advantages and disadvantages of such a configuration. There is only a community article from 2014 about this topic.
https://wiki.magnolia-cms.com/display/WIKI/Database-Only+Repositories+with+JNDI+Datasources