August 2015
Intermediate to advanced
312 pages
7h 28m
Japanese
Content preview from 初めてのSpark
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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.
269
B.3 まとめ
法があります。
しかし
DataFrame API
を利用すれば、
select
や
orderBy
などの
API
からデータに対してフィー
ルドの名前でアクセスできるため、簡潔にデータ操作を記述できます。また
Spark SQL
のオプ
ティマイザによる最適化の恩恵を受けられるメリットもあります。
一方、処理対象のデータがプレーンテキストだったり、データフォーマットがバラバラな非構造
化データを扱うのには向いていません。そのようなデータはまず
RDD
を直接操作してデータを整
形し、
DataFrame
に変換してから
DataFrame API
でデータ操作するのがよいでしょう。
B.3
め
本章では
Spark 1.3
以降の
Spark SQL
の変更点や
DataFrame API
を紹介しました。
また、
DataFrame API
の利用によって簡潔にデータ操作を記述できることに加え、オプティマ
イザの恩恵を受けられる利点があることを説明しました。
Spark 1.3
からは従来の
RDD
から
DataFrame
へと、中心となる抽象データレイヤが変化しつ
つあり、開発が活発に進んでいます。
MLlib
（
Spark ML
）では
Pipeline API
の内部で
DataFrame
を利用するなど、エコシステムについても
DataFrame
を利用したものが登場してきました。
更に
Spark 1.4
から始まった
Project Tungsten
ではオプティマイザの改良が計画されており、
こちらも目が離せません。
猿田 浩輔（さるた こうすけ） ...
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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.