It'd be interesting to see an RDBMS that actually dynamically measures the performance characteristics of the drive it's running on (by occasionally running small "fio"-like benchmarks, or by inferring them from scan execution times).

Genuinely curious: where would one expect the drive performance to fluctuate? Wear ? Lack of TRIM ? Some form of timely GC process on disk firmware ? Fragmentation or compaction of some sort ? Maybe weird shenanigans with RAID setups with disks from different vendors and batches ?

Embarking right now on a long-term embedded storage project and wondering what people actually monitor (apart from SMART and latency/throughput at app or db-level).