March 2021
Intermediate to advanced
265 pages
6h 50m
Chinese
Content preview from Presto实战
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118
｜
第
8
章
8.2
Presto
系统表
Presto
系统表
不需要配置
catalog
文件，所有的
schema
和表都在
system
catalog
中自动提供。
你可以使用
8.1
节中提到的语句来查询
schema
和表
，以了解更多关于
Presto
运行实例的信息。
可用的数据包括运行时、节点、
catalog
等，这些信息可以让你更好地理解和使用
Presto
。
PrestoWeb UI
是一个基于网页的用户界面，它显示了系统表的相关信息。更
多详细信息参见
12.1
节。
系统表包含的
schema
：
SHOW SCHEMAS IN system;
Schema
--------------------
information_schema
jdbc
metadata
runtime
(4 rows)
为了进行查询调优，表
system.runtime.queries
和
system.runtime.tasks
是最有用的：
DESCRIBE system.runtime.queries;
Column | Type | Extra | Comment
------------------------------+----------------+-------+---------
query_id | varchar | |
state | varchar | |
user | varchar | |
source | varchar | |
query | varchar | |
resource_group_id ...
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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.