Sharding / Cross-Shard Queries
Kind: tension
Record: tension:cross-shard-queries-sharding
Canonical: Schema
"sharding" (performance-core layer) is traded against "Cross-Shard Queries" (performance-core layer) — a principle cannot be scope-separated from a quality, metric, or cost it competes with; resolve by measuring "Cross-Shard Queries" and choosing an explicit operating point.
Listed in Tensions, after Load Balancing / Session Affinity and before Partitioning / Rebalancing Complexity.