I think your best choice would be to create a temporary environment to test the migration, when creating, you can copy volume data to it.

Then remove the existing Postgre and add the new one you want, them attach the old volume to the new PostgreSQL and check if it works.

If it does, them on your real environment/production/staging/etc, repeat the process, should be pretty quick and give you low down-time.

This is just how I thought of doing it... not sure it'll work, but pretty sure...

On a more safe side, no destructive actions, you could simply detach the volume from the old postgres and attach to the new one. That way you could maybe only re-attach to the old one is case it don't work, I would still try this on a dev/staging environment first.

Thanks a lot for that answer and it seems like I need to learn what the different environments are and how they work!

No worries. Refer to https://docs.railway.com/guides/environments it's all well documented :)

Hi OP, I have opened this question up to bounty as Jorge was able to help you out here. If your issue is resolved, please consider accepting their helpful reply so they may win the bounty

This gets me wondering if bounties work at all, I've seem to few 'granted' bounties, users get the answers and just bounce... Well, that's life for ya haha

Hi Jorge, I have accepted your answer so you should have gotten your bounty. If not then I guess I need support on how to accept in the right way too ;-)