Distributed DBMS: Does asynchronous replication usually slow transactions because the system spends time ensuring updates are fully propagated before commit?

Introduction / Context:
Replication strategies affect commit latency. This item differentiates between synchronous and asynchronous replication in a distributed DBMS.

Given Data / Assumptions:

• Synchronous replication confirms remote updates before commit returns.
• Asynchronous replication ships changes after commit (eventual consistency).
• Network checks and coordination add latency when performed in the critical path.

Concept / Approach:
If a system waits to “accurately and completely propagate” an update across the network before acknowledging success, it is operating synchronously. Asynchronous replication decouples propagation from the user transaction to improve perceived response time at the cost of temporary inconsistency and additional conflict handling.

Step-by-Step Solution:
Identify the behavior described: waiting for network-wide propagation during commit.Map this to synchronous replication semantics.Recognize that asynchronous replication does not wait, so response time is typically better, not worse.Conclude that the statement is incorrect for asynchronous replication.

Verification / Alternative check:
HA/DR guides show synchronous modes increasing commit latency and asynchronous modes prioritizing throughput and local responsiveness.

Why Other Options Are Wrong:
Asserting “always blocks” or “needs 2PC at every site” is incorrect for asynchronous methods. LAN/WAN scope does not change the sync/async semantic.

Common Pitfalls:
Assuming asynchronous means “fast and exact” or “no ordering issues.” It improves latency but requires reconciliation and careful conflict resolution policies.

Final Answer:
Does not apply — the description matches synchronous replication, not asynchronous