August 2024
Intermediate to advanced
392 pages
10h 4m
Japanese
Content preview from 達人に学ぶDB設計徹底指南書 第2版
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
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前章までで、リレーショナルデータベースにおける論理設計の基本を学習しまし
た。その中核となる概念が正規化でした。ここでもう一度、なぜ正規化する必要が
あるか、そのメリットは何か、というところをまとめると、それはひとえに、デー
タの整合性を保持するためでした。データベースというのは、ユーザーの利用する
データを一元的に集約して保管する倉庫です。したがって、ここに含まれるデータ
が間違っている、ということは絶対に許されません。正規化は、この厳しい要求に
応えるためデータ整合性を厳密に保つ方法論です。
しかし一方で、正規化がもたらすのは良いことばかりではありません。世の中の
たいていのことに表と裏があるように、正規化にも副作用があります。それもかな
り強いものが。それは、正規化されたテーブル群に対するSQLが非常に遅くなっ
てしまい、しばしばシステムとして実用にたえないぐらい、パフォーマンス劣化を
招いてしまうことです。
本章では、そうした正規化の負の側面を明らかにするとともに、それに対して現
場のエンジニアはどのような対処を取るべきか、という点を学習していきます。
まずは、第3 正規化した状態のテーブル群から始めましょう。
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5-1
C0001 000A 加藤 40 D01
C0001 000B 藤本 32 D02
C0001 001F 三島 50 D03
C0002 000A
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.