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.
ここまでは特に問題はなく、どこのBI/DWH の運用現場でも行なわれているあ
りふれた話です。問題になるのは、データマートというのがわりとユーザーからの
アドホックな要請に基づいて気軽に作られがちで、もう不要になったのに設計書が
残っていないため誰も怖くて削除できなくなるとか、同じようなテーブル定義なの
に以前作ったマートの設計書が残っていないためまた似たようなマートが作られる
ということが積み重なっていったときです。中には数年間誰もアクセスしないのに
詳細が不明なため怖くて削除できないという最悪の状況に陥っているケースもあり
ます。こうした幽霊のようなマートをと呼びます。ゾンビマートは、
ストレージの容量を無駄に食うため、オンプレミスにおいてもクラウドにおいても
問題となります（オンプレミスでは容量は上限に当たらない限りコスト増にならな
いと思われるかもしれませんが、データが増えるとそれだけバックアップや夜間
バッチのデータ同期処理を遅延させるなどの弊害があります）。
こうなってしまうとデータマートというのも良し悪しです。データマートはデー
タベースに作るキャッシュとしての性格も持つので、パフォーマンス改善にはしば
しば劇的な効果を発揮します。しかし、効果的だとわかると次々にアドホックに作
られ始めます。ここまでくると、データマートというのは外部スキーマの出来損な
いなのではないかという疑念が強くなってきます。いっそDWH 専用データベース
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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.