Difficulty: Easy
Correct Answer: Does not apply — immediate, all-site updates describe synchronous behavior
Explanation:
Introduction / Context:
This question contrasts asynchronous with synchronous replication timing guarantees.
Given Data / Assumptions:
Concept / Approach:
The statement describes the synchronous guarantee (all-or-abort across all copies before commit returns). Asynchronous replication improves availability and latency by decoupling propagation, accepting temporary divergence among replicas.
Step-by-Step Solution:
Identify “immediately applied everywhere” as a sync property.Recall async behavior: commit locally first; ship and apply later.Conclude the given behavior is not asynchronous.
Verification / Alternative check:
System docs for popular databases detail synchronous commit semantics versus eventual consistency of asynchronous modes.
Why Other Options Are Wrong:
LAN speed, semijoins, or shared logs do not redefine asynchronous semantics.
Common Pitfalls:
Expecting read-your-write consistency across sites immediately after a local commit in async setups.
Final Answer:
Does not apply — immediate, all-site updates describe synchronous behavior
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