読書会(データ指向アプリケーションデザイン)第10回議事録

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Java読書会BOF「データ指向アプリケーションデザイン」を読む会第10回
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.. csv-table:: 開催概要

  "日時", "2021年7月24日 10:00 - 17:00"

  "場所", "てくのかわさき第4研修室"
  "出席者(敬称略)", "松永、平山、岩室、加藤、遠藤、高橋(徹)"

* 本日はp558 12.2.3から読書開始です。

12章データシステムの将来
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12.2 データベースを解きほぐす
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12.2.3 導出された状態の監視
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* P558

  * 書き込みは先行評価で、読み込みは遅延評価ってどういう意味？
  * ユーザから見て、意味のある機能を提供するのは、読み取りだから遅延評価？

12.2.3.1 マテリアライズドビューとキャッシュ
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12.2.3.2 ステートフルでオフライン動作できるクライアント
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12.2.3.3 クライアントへの状態の変化のプッシュ
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12.2.3.4 エンドツーエンドのイベントストリーム
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* P562 こういう設計します？

  * 組み込みでは当たり前。
  * よくwebsocketで逆向きを実現するなぁ
  * 北海道では電波の繋がらないことが多いのでオフライン必要

12.2.3.5 読み取りもイベントである
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12.2.3.6 複数パーティションにわたるデータの処理
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12.3 正確性を求めて
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12.3.1 データベースのエンドツーエンド論
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12.3.1.1 操作を厳密に一度だけ実行する
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12.3.1.2 重複の抑制
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12.3.1.3 操作識別子
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12.3.1.4 エンドツーエンド論
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12.3.1.5 データシステムへのエンドツーエンドの考え方の適用
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* P570

  * 分散トランザクションは自分で作ってはいけない

12.3.2 制約の強制
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12.3.2.1 ユニーク制約には合意が必要
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12.3.2.2 ログベースのメッセージングにおけるユニーク性
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12.3.2.3 マルチパーティションのリクエスト処理
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12.3.3 適時性と整合性
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12.3.3.1 データフローシステムの正確性
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12.3.3.2 制約の緩やかな解釈
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* P576

  * 補正トランザクションはが必要かどうかはいつ気づくのか？
  * クライアント次第

* ナチュラルキーを使うか、サロゲートキーを使うか

  * redmineの移行でサロゲートキーが邪魔で手間取った
  * redmineのチケットidはナチュラルキーか？サロゲートキーか？それとも両方か？

12.3.3.3 調整を回避するデータシステム
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12.3.4 信頼しつつも検証を
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12.3.4.1 ソフトウェアのバグがあっても整合性を保つ
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12.3.4.2 約束を単純に盲信してはならない
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* P580

  * バックアップはするけど、リストアはしませんよね。
  * バックアップが壊れたことはある。リストあできることも試して置かないといけない

12.3.4.3 検証の文化
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12.3.4.4 監査性のための設計
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12.3.4.5 エンドツーエンド論再び
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12.3.4.6 監査可能なデータシステムのためのツール
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12.4 正しいことを行う
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12.4.1 予測分析
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12.4.1.1 バイアス(偏見)と差別
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12.4.1.2 責任と説明責任
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12.4.1.3 フィードバックループ
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12.4.2 プライバシーと追跡
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12.4.2.1 監視
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12.4.2.2 承諾と選択の自由
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12.4.2.3 プライバシーとデータの利用
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12.4.2.4 資産や権力としてのデータ
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12.4.2.5 産業革命を忘れない
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12.4.2.6 法律と自己規制
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まとめ
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用語集
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本日は「データ指向アプリケーションデザイン」を読み終えました。

次回は新しい課題図書になります。

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