August 2015
Intermediate to advanced
312 pages
7h 28m
Japanese
Content preview from 初めてのSpark
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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.
23
3
RDD
グラング
本章では、
Spark
でデータを扱う上で核となる抽象化を行う、耐障害性分散データセット
（
RDD
：
Resilient Distributed Dataset
）を紹介します。
RDD
は、分散された要素のコレクション
にすぎません。
Spark
では、すべての作業は新しい
RDD
の生成、既存の
RDD
の変換、結果を計
算するための
RDD
に対する操作の呼び出しのいずれかとして表現されます。舞台裏では、
Spark
は
RDD
に含まれるデータを自動的にクラスタ内に分散させ、
RDD
に対する操作を並列化します。
RDD
は、
Spark
の中核となる概念なので、本章はデータサイエンティストの方もエンジニアの
方も読んでください。本章のサンプルの少なくともいくつかを、実際にインタラクティブシェルか
ら試してみることを強くお勧めします（「
2.2 Spark
の
Python
および
Scala
シェルの紹介」参照）。
加えて、本章のすべてのコードは、本書の
GitHub
リポジトリ（
https://github.com/databricks/
learning-spark
）から入手できます。
3.1
RDD
の
Spark
における
RDD
は、イミュータブルなオブジェクトの分散コレクションにすぎません。
それぞれの
RDD
は、複数のーに分割されており、それぞれに対する演算処理がク
ラスタの各ノード上で行われることがあります。
RDD
には、ユーザーが定義したものを含め、
Python
、
Java
、
Scala
の任意の種類のオブジェクトを持たせることができます。 ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
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.