Before we get to into how to connect to a remote database in Resolve, please follow my guide on how to set up a dockerized PostgreSQL db for Davinci Resolve (or any other program that connects to PostgreSQL dbs)
PostgreSQL - Multiple DBs in One Instance - Compose
Connecting to remote DB over LAN
Open Resolves Project Manager. Go to Network → Add Project Library. Select Connect.
Name is the name of the database (This MUST be the name of the db in PostgreSQL. You can not set this to whatever you want independent of what is in PostgreSQL!).
Location is the LAN IP of the computer hosting your DB. (You could MAYBE get this to work over WAN using a VPN, but I haven’t tried it and the performance would most probably be terrible anyway)
Username and Password should be set to postgres if you followed my guide.
Extract info from already connected DB
If you want to find out the connection info for a database that your already connected to, go to Details for the database in question, then click Share Key and save the “.resolvedbkey” file to easily accessible directory.
Then open that file in a text editor.
The IP address, database name, username and password used in connecting is all there.