November 2017
Intermediate to advanced
328 pages
6h 51m
Japanese
Content preview from 入門 PySpark ―PythonとJupyterで活用するSpark 2エコシステム
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.
1.3
Spark 2.0
のアーキテクチャ
9
1.3.1
Dataset
と
DataFrame
の統合
前セクションでは、Datasetは（現時点では）ScalaとJava でしか利用できないと述べました。とは
いえ、Spark 2.0 の方向性の理解に役立つことから、Datasetについても次に説明します。
Datasetは、2015年に Apache Spark 1.6リリースの一部として登場しました。Dataset が目標として
いたのは、型安全なプログラミングインターフェイスを提供することでした。これによって、開発者は半
構 造 化 データ（たとえば JSON やキー－バリューのペアなど）をコンパイル時点での型安全性の下で扱
えるようになりました（すなわちプロダクションアプリケーションを実行前にエラーチェックできるよう
に な っ た の で す ）。 PythonでDataset API が実装されていない理由の一部は、Pythonが型安全な言語
ではないためです。
同じように重要なこととして、Dataset APIには
sum()
、
avg()
、
join()
、
group()
といった
高レベルのドメイン固有言語の操作が含まれています。この特徴が意味しているのは、これまでの
Spark RDDの柔軟性を保ちながらコードの表現力や読み書きのしやすさが高まるということです。
DataFrameと同じく、Datasetも式やデータフィールドをクエリプランナーに渡し、Tungstenの高速
なインメモリエンコー ...
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.