We are coming over from Heroku and there was something else that made observability better there: private space/shielded apps would send metric samples to syslog:
source=DATABASE addon=postgresql-name-changed sample#current_transaction=2174472406 sample#db_size=95053636463bytes sample#tables=178 sample#active-connections=23 sample#waiting-connections=0 sample#index-cache-hit-rate=0.93479 sample#table-cache-hit-rate=0.85376 sample#load-avg-1m=0.005 sample#load-avg-5m=0.035 sample#load-avg-15m=0.04 sample#read-iops=2.3267 sample#write-iops=0.09901 sample#tmp-disk-used=543633408 sample#tmp-disk-available=72435159040 sample#memory-total=16070708kB sample#memory-free=160880kB sample#memory-cached=14870684kB sample#memory-postgres=252416kB sample#wal-percentage-used=0.06650494233193834
It's great. You can then use your log analysis graphing feature on any of these metrics you are concerned with. Of course, it would be great to have these stats available on the Render dashboard for Postgres instead.