TUNING / MEASURE BEFORE CHANGING

Read caching, merge costs, and storage sizing

Compare a representative workload against the default configuration, then use read latency, merge I/O, file shape, or payload cost to choose an experiment.

Make each experiment comparable
  1. Fix the dataset, key distribution, payload sizes, concurrency, and query bounds.
  2. Separate cold and warm reads, and state the engine-cache and OS-cache conditions.
  3. Change one control or coupled target range, and record the exact options.
  4. Compare latency distributions, throughput, allocations, retained memory, and I/O through a representative maintenance cycle.