openGauss的模式是对数据库做一个逻辑分割。所有的数据库对象都建立在模式下面。openGauss的模式和用户是弱绑定的，所谓的弱绑定是指虽然创建用户的同时会自动创建一个同名模式，但用户也可以单独创建模式，并且为用户指定其他的模式。
在一个数据库中，可以有多个模式。模式可以把一组对象组织在一起。这样组织机构有多少个应用，我们可以将数据库对象组织成几个模式；组织机构有几个部门，也可以为该部门创建单独的模式。默认情况下，用户将访问数据库的public模式。
学习目标
模式管理包括为数据库创建模式、删除模式、查看和设置模式的搜索路径、查看模式中的信息。
课程作业
1.1 创建一个名为testsm、testsm1的模式
root@modb:~# su - omm
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.
omm=# create schema testsm;
CREATE SCHEMA
omm=# create schema testsm1;
CREATE SCHEMA
omm=#
omm=# \dn
List of schemas
Name | Owner
sqladvisor | omm
testsm | omm
testsm1 | omm
user1 | user1
(16 rows)-----------------+-------
blockchain | omm
cstore | omm
db4ai | omm
dbe_perf | omm
dbe_pldebugger | omm
dbe_pldeveloper | omm
pkg_service | omm
public | omm
schm1 | user1
schm2 | omm
schm3 | omm
snapshot | omm
omm=# \du
List of roles
Role name | Attributes
| Member of
-----------+-----------------------------------------------------------------------------------------------------------
-------+-----------
gaussdb | Sysadmin
| {}
omm | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin,
UseFT | {}
user1 | Sysadmin
| {}
1.2 创建一个用户john, 并将testsm的owner修改为john，且修改owner前后分别使用\dn+查看模式信息
omm=#
omm=# alter user john sysadmin ;
ALTER ROLE
omm=# create user john identified by 'kunpeng@1234';
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# \dn+
List of schemas
Name | Owner | Access privileges | Description | WithBlockChain
dbe_pldebugger | omm | omm=UC/omm +| dbe_pldebugger schema | f
| | =U/omm | |
-----------------+-------+-------------------+----------------------------------+----------------
blockchain | omm | | blockchain schema | f
cstore | omm | | reserved schema for DELTA tables | f
db4ai | omm | omm=UC/omm +| db4ai schema | f
| | =U/omm | |
dbe_perf | omm | | dbe_perf schema | f
dbe_pldeveloper | omm | omm=UC/omm +| dbe_pldeveloper schema | f
| | =U/omm | |
john | john | | | f
pkg_service | omm | | pkg_service schema | f
schm1 | user1 | | | f
schm2 | omm | | | f
public | omm | omm=UC/omm +| standard public schema | f
| | =U/omm | |
sqladvisor | omm | omm=UC/omm +| sqladvisor schema | f
| | =U/omm | |
testsm | omm | | | f
schm3 | omm | | | f
snapshot | omm | | snapshot schema | f
testsm1 | omm | | | f
user1 | user1 | | | f
(17 rows)
omm=# alter schema testsm owner to john ;
ALTER SCHEMA
omm=# \dn+
List of schemas
Name | Owner | Access privileges | Description | WithBlockChain
-----------------+-------+-------------------+----------------------------------+----------------
blockchain | omm | | blockchain schema | f
cstore | omm | | reserved schema for DELTA tables | f
db4ai | omm | omm=UC/omm +| db4ai schema | f
| | =U/omm | |
schm2 | omm | | | f
schm3 | omm | | | f
dbe_perf | omm | | dbe_perf schema | f
dbe_pldebugger | omm | omm=UC/omm +| dbe_pldebugger schema | f
| | =U/omm | |
dbe_pldeveloper | omm | omm=UC/omm +| dbe_pldeveloper schema | f
| | =U/omm | |
john | john | | | f
pkg_service | omm | | pkg_service schema | f
public | omm | omm=UC/omm +| standard public schema | f
| | =U/omm | |
schm1 | user1 | | | f
| | =U/omm | |
testsm | john | | | f
--More-- snapshot | omm | | snapshot schema | f
sqladvisor | omm | omm=UC/omm +| sqladvisor schema | f
testsm1 | omm | | | f
user1 | user1 | | | f
(17 rows)
1.3 重命名testsm为testsm2
omm=# alter schema testsm rename to testsm2;
ALTER SCHEMA
omm=# \dn+
List of schemas
Name | Owner | Access privileges | Description | WithBlockChain
-----------------+-------+-------------------+----------------------------------+----------------
blockchain | omm | | blockchain schema | f
cstore | omm | | reserved schema for DELTA tables | f
db4ai | omm | omm=UC/omm +| db4ai schema | f
| | =U/omm | |
dbe_perf | omm | | dbe_perf schema | f
dbe_pldebugger | omm | omm=UC/omm +| dbe_pldebugger schema | f
| | =U/omm | |
dbe_pldeveloper | omm | omm=UC/omm +| dbe_pldeveloper schema | f
| | =U/omm | |
john | john | | | f
pkg_service | omm | | pkg_service schema | f
public | omm | omm=UC/omm +| standard public schema | f
| | =U/omm | |
schm1 | user1 | | | f
schm2 | omm | | | f
schm3 | omm | | | f
snapshot | omm | | snapshot schema | f
sqladvisor | omm | omm=UC/omm +| sqladvisor schema | f
| | =U/omm | |
testsm1 | omm | | | f
testsm2 | john | | | f
user1 | user1 | | | f
(17 rows)
1.4 在模式testsm1中建表t1、插入记录和查询记录
omm=# create table testsm1.t1
omm-# ( c_customer_sk integer,
omm(# c_customer_id char(5),
omm(# c_first_name char(6),
omm(# c_last_name char(8)
omm(# );
CREATE TABLE
omm=# insert into testsm1.t1 values
omm-# (4321, 2, 'Lily','Carter'),
omm-# (6885, 1, 'Joes', 'Hunter'),
omm-# (9527, 3, 'James', 'Cook'),
omm-# (9500, 4, 'Lucy', 'Baker');
INSERT 0 4
omm=# select * from testsm1.t1 ;
c_customer_sk | c_customer_id | c_first_name | c_last_name
---------------+---------------+--------------+-------------
6885 | 1 | Joes | Hunter
4321 | 2 | Lily | Carter
9527 | 3 | James | Cook
9500 | 4 | Lucy | Baker
(4 rows)
1.5 在会话级设置模式搜索顺序
omm=# show SEARCH_PATH;
search_path
----------------
"$user",public
(1 row)
omm=# set SEARCH_PATH to testsm;
SET
omm=# show SEARCH_PATH;
search_path
-------------
testsm
(1 row)
omm=# \q
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.
omm=# show SEARCH_PATH;
search_path
----------------
"$user",public
(1 row)
1.6 在数据库级设置模式搜索顺序
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.
omm=# show SEARCH_PATH;
search_path
-------------
testsm
(1 row)
1.7 在用户级设置模式搜索顺序
omm=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
(5 rows)
omm=# -----------+-------+----------+---------+-------+-------------------
enmdb | omm | UTF8 | C | C |
omm | omm | UTF8 | C | C |
postgres | omm | UTF8 | C | C |
template0 | omm | UTF8 | C | C | =c/omm +
| | | | | omm=CTc/omm
template1 | omm | UTF8 | C | C | =c/omm +
| | | | | omm=CTc/omm
omm=# alter user omm set SEARCH_PATH to testsm1;
ALTER ROLE
omm=# \q
omm@modb:~$ gsql -d postgres -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.
openGauss=# show SEARCH_PATH;
search_path
-------------
testsm1
(1 row)
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