The index we build by default to support query-based reopening can lead to about a 10% decrease in throughput for bulk insert workloads, and up to 30% increase in median latency for individual inserts. We can probably improve this by building the index directly on the system.buckets collection over {meta: 1, control.min.time: 1} rather than using the standard rewrite ({meta: 1, control.min.time: 1, control.max.time: 1}) to decrease the frequency of index key updates.

Additionally, we could potentially skip calculating index keys if we know the underlying fields haven't changed.