March 2021
Intermediate to advanced
265 pages
6h 50m
Chinese
Content preview from Presto实战
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94
｜
第
6
章
6.7
黑洞连接器
黑洞连接器
可以很容易地在
catalog
属性文件
（如
etc/catalog/blackhole.properties
）中配置
使用。
connector.name=blackhole
它作为任何数据的最终消费者，类似于
UNIX
操作系统中的
null
设备（
/dev/null
）。你可以
把它作为从其他
catalog
中读取并插入数据的目标。因为它实际上不写入任何内容，
所以你
可以用它来衡量从这些
catalog
中读取数据的性能。
例如，你可以在
blackhole
中创建名为
test
的
schema
，并从
tpch.tiny
数据集中创建一个
表。然后从
tpch.sf3
中读取一个数据集，并将其插入
blackhole
catalog
中。
CREATE SCHEMA blackhole.test;
CREATE TABLE blackhole.test.orders AS SELECT * from tpch.tiny.orders;
INSERT INTO blackhole.test.orders SELECT * FROM tpch.sf3.orders;
这个操作本质上是衡量从
tpch
catalog
中读取性能，它读取了
150
万条订单记录，然后将
其发送到
blackhole
。使用其他模式（如
tcph.sf100
）会增加数据集的大小。这可以用来
评估你的
Presto
集群的性能。
可以用
RDBMS
、对象存储或键值存储
catalog
进行类似的查询
，帮助我们进行查询开发、
性能测试及改进。
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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.