Scale Postgres VMs
See Monitoring for how to check the current sizes of the VMs in your Postgres cluster.
Scale VM resources for each Machine in the cluster with the
flyctl machine update command. Here's an example of scaling RAM to 1GB on a machine:
fly machine update e784079b449483 --memory 1024 --app pg-test
You can use
fly machine status again to confirm the new scale of the Machine.
If you have more than one instance in the primary region cluster, scale these VMs identically; they are meant to be interchangeable so the cluster can fail over in case of trouble.
Postgres Resource Parameters
When you created your Fly Postgres cluster, certain Postgres configuration parameters were set to sensible values for the resources being provisioned. This means you may want, or need, to change them if you scale your VM resources. Read Configuration Tuning before scaling down!