Readonly postgres database on Dropbox

Question

This is on several MacBook Pros and iMac, all running Monterey (OSX 12.3)

I would like to store a readonly postgres database on my Dropbox, so that I can use access it from multiple computers. I realize storing a writeable database is unworkable, but I'm not trying to do that.

I created a database under /Users/me/Dropbox/dbs on my MacBook Pro. But the other machines don't see the contents of the directory.

I figured it was because postgres has a different UID on the various machines, so I tried doing chown -R me:staff on the db database directory on the MacBook Pro. That made the directories and their contents visible in the Dropbox on the other machines, but I can't start postgres on the MacBook Pro (haven't tried elsewhere yet), because of file permissions, even after making the complained of file go=rx. I'm thinking since the file is in group=staff and not in postgres that's not going to work.

Any ideas? For example: can I create the database as me:staff, rather and postgres:postgres?

Answer 1

Like Laurenz says, this is never going to work properly. The closest you could get I suspect is some foreign data wrapper to the read-only shared directory. That's not going to provide the experience you are looking for I suspect though.

The SQLite wrapper might be your best bet. Store the shared data in SQLite and access it through PG. https://github.com/pgspider/sqlite_fdw

Answer 2

PostgreSQL is not Microsoft Access, it is a relational database with a client-server architecture. It works by starting the database server on the data directory and then connecting to the server process with a client. You can only run a single instance of the database server on a single data directory, and that is all you need, since many clients can connect to the server at the same time. The database directory has to be writable by the server and indeed is modified, even if you only perform read operations in the database.