March 2021
Intermediate to advanced
265 pages
6h 50m
Chinese
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122
｜
第
8
章
在每个连接器中，
Information Schema
都有
8
个视图。对于某些不支持的功能（例如角色）
的连接器，查询对应的
InformationSchema
可能会产生一个不支持的错误：
SHOW TABLES IN system.information_schema;
Table
------------------
applicable_roles
columns
enabled_roles
roles
schemata
table_privileges
tables
views
(8 rows)
注意，在你通过
Information Schema
查询
schema
中的表时，也会返回
Information Schema
自身拥有的表：
SELECT * FROM hive.information_schema.tables;
table_catalog | table_schema | table_name | table_type
---------------+--------------------+------------------+----------
hive | web | nation | BASE TABLE
hive | information_schema | enabled_roles | BASE TABLE
hive | information_schema | roles | BASE TABLE
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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.