When are replicated databases preferred? Are they favored for workloads that are mostly read-only with relatively static data?

Introduction / Context:
Replication trades off write complexity and consistency coordination for improved read availability and locality. The suitability depends on workload characteristics.

Given Data / Assumptions:

• Workload is dominated by reads; writes are less frequent.
• Data changes are relatively infrequent (static compared to read volume).
• Replica freshness requirements are compatible with the chosen sync mode.

Concept / Approach:
Read-mostly systems gain by serving queries from many replicas close to users while batching or asynchronously applying updates. Highly write-intensive, hot-spot workloads face overhead from propagating each change to all replicas, risking conflicts and lag.

Step-by-Step Solution:
Assess read/write ratio and update frequency.Match replication mode (sync/async) to staleness tolerance.Place replicas near consumers to reduce latency.Confirm the approach improves availability and performance.

Verification / Alternative check:
Many CDNs and global services replicate state that changes slowly (catalogs, profiles, reference data) for scalability.

Why Other Options Are Wrong:
Write-heavy workloads magnify replication cost; hardware uniformity and semijoins are unrelated requirements.

Common Pitfalls:
Underestimating conflict resolution in multi-writer topologies; ignoring replication lag for read-your-write scenarios.

Final Answer:
Applies — read-mostly and slow-changing data suit replication well