問77
頻出度★☆☆
次の a～d のうち, DBMSに備わる機能として, 適切なものだけを全て挙げたものはどれか。 a ウイルスチェック b データ検索・更新 c テーブルの正規化 d 同時実行制御
平成28年度 秋期 ITパスポート試験 問77
テクノロジ系データベース › データベース方式
This question's explanation and your answers so far.
解説
問 77
Incorrectア
This is the combination a, b, c, but a virus checking is the job of antivirus software, not a DBMS function, and c table normalization is work done by a designer during the database design process, not a function that a DBMS automatically provides. Since it includes the wrong items a and c and also lacks the correct item d, it is inappropriate.
Incorrectイ
This is the combination a, c, but neither a virus checking nor c table normalization is a DBMS function. Since it contains none of the DBMS functions b and d at all, it is inappropriate.
Incorrectウ
This is the combination b, c, d. Although b data search and update and d concurrency control are correct, it wrongly includes c table normalization. Normalization is work done at the stage of designing the data structure, not a function that a DBMS provides, so as an option meant to list “only the functions” it is inappropriate.
- エ
正解 The correct answer is エ (b, d). A DBMS (database management system) is software for handling data shared by many users safely and efficiently, and its core functions are “data search and update” and “concurrency control.” b Data search and update is the most basic role of a DBMS: querying, adding, modifying, and deleting data via SQL and the like. d Concurrency control (lock-based control) is a function that keeps data consistent by means such as locking, so that no contradiction arises even when multiple users or transactions access the same data at the same time; this too is provided by a DBMS. Therefore, the option that lists exactly the DBMS functions with nothing extra and nothing missing is エ, the combination of b and d.
ここがポイント
- The main functions of a DBMS include data search and update (data manipulation), concurrency control (lock-based control), failure recovery, and confidentiality protection (access control); at their core is a mechanism for keeping data shared by multiple users consistent and secure.
- Distinguish clearly that normalization is work performed by people during the database design process and virus checking is the role of antivirus software—neither is a function that the DBMS itself provides.
用語