Hard Cutover — Page 3

Analytics databases now face machine-driven queries that violate three core design assumptions.

Observability catches silent data failures that monitoring dashboards never flag.

Kappa simplifies one codebase but makes replay affordable only with the right storage layer.

Deduplication only works when three conditions align, and production breaks when they don't.

Staging environments don't replicate the shard fan-out and contention that reveal real tail latency.

Hidden query costs multiply when volumes scale beyond manual controls and caching breaks.

S3 routing multiplies latency penalties across your cluster as it grows instead of reducing it.

Test a database provider swap against real traffic before fully committing.

Some MergeTree settings vanish, lock, or silently override when moving to managed platforms.

Rewriting sort keys and shard logic prevents silent performance cliffs during OLAP migrations.