問78
頻出度★★☆
DBMS において, あるサーバのデータを他のサーバに複製し, 同期をとることで, 可用性や性能の向上を図る手法のことを何というか。
平成29年度 春期 ITパスポート試験 問78
テクノロジ系システム構成要素 › システムの構成
This question's explanation and your answers so far.
解説
問 78
Incorrectア
Archiving means moving and storing old, less frequently used data onto another medium for long-term preservation. Its purpose differs from improving availability through copying and synchronization, so it is incorrect.
Incorrectイ
A journal is a log that records updates made to a database in chronological order, and is used for recovery through rollback or rollforward when a failure occurs. It is not a technique for copying and synchronizing data between servers, so it is incorrect.
Incorrectウ
A distributed transaction is a process that guarantees that a series of updates spanning multiple databases or servers are either all committed or all rolled back. It is a mechanism for maintaining consistency, not itself a technique for raising availability by copying data, so it is incorrect.
- エ
正解 The correct answer is “エ Replication”. Replication is a technique that places a copy (duplicate) of the data held by one server onto another server and keeps the contents of both synchronized. Because the same data is held on multiple servers, processing can continue on the other servers even if one fails, which raises availability; and because read requests can be distributed across multiple servers, performance also improves. The wording in the question, “copying data to other servers and keeping them synchronized” and “improving availability and performance”, matches the definition of replication exactly.
ここがポイント
- Grasp the definition: replication is a technique that copies and synchronizes data to raise availability and performance.
- Distinguish it from related terms: archive (long-term storage), journal (update log), and distributed transaction (consistency guarantee across multiple databases).
用語