August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
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.
｜
411
在数据中使用标识符和键
由此产生的流程看起来如图
46-12
所示，尽管你可能希望添加输出来使用数据或将
其写入需要使用的地方。完整的数据集现在只有
Category ID
（类别
ID
），而没有
类别名称。这样可以节省空间，并且可以更快地进行处理。如果需要将名称添加回
数据集，可以使用参考表。
图
46
-
12
：在流程的一个单独分支上使用汇总步骤创建参考表
如果需要更新数据集，可增加
Category
（类别）字段中的潜在值数量，但一定要保
留原来的
ID
集，并将下一个排名值分配给新的值。
46.5
小结
当你刚开始准备数据时，
Key
（键）和
ID
（标识符）似乎会带来不必要的困难。然而，
通过更快的计算速度和更少的存储空间，可以减少完成分析所需的时间和存储数据
的成本，特别是当数据集变得更大时。
Prep Builder
可以帮助你看到将参考表加入数
据中的效果，这是验证是否使用了正确的键值的好方法。还可以使用
Prep Builder
创建你自己的参考表，并将其写入数据库中。
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.