PostgreSQL service stores all snapshot data collected by the snapshot workers.
This service is deployed using Fly.io PostgreSQL App.
Create new postgresql app on fly.io:
flyctl postgres create
You need to connect to fly.io postgress locally, please read the following documentation.
Connect to the postgresql using any PostgreSQL client, for example you may use PGAdmin.
Then create new database for each network, for example snapshot_kovan.
Then you will have the following connection url:
postgres://postgres:SECRET@snapshot-postgresql.internal:5432/DATABASE
Use this connection url for the app.