openGauss每日一练第 6 天 |openGauss创建模式、修改模式属性和删除模式

学习openGauss的第六天

主要内容是学习openGauss创建模式、修改模式属性和删除模式
模式是一组数据库对象的集合，主要用于控制对数据库对象的访问

登录数据库
root@modb:~# su - omm
omm@modb:~$ gsql -r
gsql ((openGauss 2.0.0 build 78689da9) compiled at 2021-03-31 21:03:52 commit 0 last mr )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# \dn
List of schemas
Name | Owner
-------------+-------
cstore | omm
dbe_perf | omm
pkg_service | omm
public | omm
snapshot | omm
(5 rows)

omm=# \dn+
List of schemas
Name | Owner | Access privileges | Description
-------------+-------+-------------------+----------------------------------
cstore | omm | | reserved schema for DELTA tables
dbe_perf | omm | | dbe_perf schema
pkg_service | omm | | pkg_service schema
public | omm | omm=UC/omm +| standard public schema
| | =U/omm |
snapshot | omm | | snapshot schema
(5 rows)

1.创建一个名为tpcds的模式

omm=# create schema tpcds ;
CREATE SCHEMA
omm=# \dn+ tpcds
List of schemas
Name | Owner | Access privileges | Description
-------+-------+-------------------+-------------
tpcds | omm | |
(1 row)


2.创建一个用户tim, 并将tpcds的owner修改为tim，且修改owner前后分别使用\dn+查看模式信息

omm=# create user tim identified by 'user_123' ;
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
omm=# CREATE ROLE

omm=# \dn+ tpcds
List of schemas
Name | Owner | Access privileges | Description
-------+-------+-------------------+-------------
tpcds | omm | |
(1 row)

omm=# alter schema tpcds owner to tim ;
omm=# ALTER SCHEMA

omm=# \dn+ tpcds
List of schemas
Name | Owner | Access privileges | Description
-------+-------+-------------------+-------------
tpcds | tim | |
(1 row)


3.重命名tpcds为tpcds1

omm=# alter schema tpcds rename to tpcds1 ;
ALTER SCHEMA

4.在模式tpcds1中建表customer、插入记录和查询记录
omm=# create table tpcds1.custom(id integer) ;
CREATE TABLE

omm=# insert into tpcds1.custom values(1) ;
INSERT 0 1
omm=# select * from tpcds1.custom ;
id
----
1
(1 row)


5.删除模式tpcds1

omm=# drop schema tpcds1 ;
ERROR: cannot drop schema tpcds1 because other objects depend on it
DETAIL: table tpcds1.custom depends on schema tpcds1
HINT: Use DROP ... CASCADE to drop the dependent objects too.
omm=# drop schema tpcds1 cascade ;
NOTICE: drop cascades to table tpcds1.custom
DROP SCHEMA
omm=# \dn
List of schemas
Name | Owner
-------------+-------
cstore | omm
dbe_perf | omm
pkg_service | omm
public | omm
snapshot | omm
tim | tim
(6 rows)