Monitor bloat estimate
We need to measure bloat in the database to remove the need to manually measure it. Bloat can only be measured accurately on a one-off database and is a offline and rather expensive operation. Hence, we aim to estimate bloat with standard methods and push this information to prometheus.
Ideally, the bloat estimate should be available in prometheus for
- individual indexes,
- individual tables (heap + toast),
- overall index bloat (can be derived) and
- overall table bloat (can be derived).
It's ok if the bloat estimate only gets updated a few times a day, if a high frequency of measurements is not feasible.