March 2021
Intermediate to advanced
265 pages
6h 50m
Chinese
Content preview from Presto实战
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生产环境中的
Presto
｜
233
子资源组也必须指定
query_priority
。
权重调度
将
schedulingPolicy
设置为
weighted_fair
，
这
用于选择启动下一个查询的子资源组。此
策略需要配合
schedulingWeight
属性使用：调度器将基于子资源组的
schedulingWeight
按比例选择查询。
12.8.3
选择器规则定义
选择器规则
（
selector
rule
）必须定义
group
属性，此属性决定将查询分配到哪个资源组。
最好将文件中的最后一个选择器设置为只有
group
属性的规则，它将为所有查询显式指定
一个默认组。
可以使用可选属性和正则表达式定义选择器规则。
user
匹配用户名。可以使用正则表达式来匹配多个名称。
source
匹配查询来源，例如
presto-cli
或
presto-jdbc
。可以使用正则表达式进行匹配。
queryType
匹配查询类型，可选项包括
DATA_DEFINITION
、
DELETE
、
DESCRIBE
、
EXPLAIN
、
INSERT
和
SELECT
。
clientTags
匹配提交查询的客户端指定的客户端标签。
你可以使用
--source
或
--client-tags
选项在
PrestoCLI
上指定查询来源和客户端标签：
$ presto --user mfuller --source mfuller-cli
$ presto --user mfuller --client-tags adhoc-queries
12.9
小结
恭喜！你已经和
Presto
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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.