openGauss每日一练第5天|opengauss中一个用户可以访问多个数据库

数据库用户user1可以访问不同的数据库（musicdb1、musicdb2、musicdb3）。

实验需求：

user1用户在数据库musicdb1中创建了表t11；

user1用户在数据库musicdb2中创建了表t21；

user1用户在数据库musicdb3中创建了表t31；

1 切换至omm用户

[root@enmoedu ~]# su - omm
Last login: Mon Nov 28 03:19:57 CST 2022 on pts/1
[omm@enmoedu ~]$ 

[omm@enmoedu ~]$ gs_om -t status --detail
[   Cluster State   ]

cluster_state   : Unavailable
redistributing  : No
current_az      : AZ_ALL

[  Datanode State   ]

    node   node_ip         port      instance                            state
----------------------------------------------------------------------------------------------
1  enmoedu 192.168.94.135  15400      6001 /opt/huawei/install/data/dn   P Primary Manually stopped
[omm@enmoedu ~]$

• 将数据库拉起

[omm@enmoedu ~]$ gs_om -t start 
Starting cluster.
=========================================
[SUCCESS] enmoedu
2022-11-28 22:33:45.469 6384c6c8.1 [unknown] 139681239907392 [unknown] 0 dn_6001 01000  0 [BACKEND] WARNING:  could not create any HA TCP/IP sockets
2022-11-28 22:33:45.469 6384c6c8.1 [unknown] 139681239907392 [unknown] 0 dn_6001 01000  0 [BACKEND] WARNING:  could not create any HA TCP/IP sockets
2022-11-28 22:33:45.506 6384c6c8.1 [unknown] 139681239907392 [unknown] 0 dn_6001 01000  0 [BACKEND] WARNING:  Failed to initialize the memory protect for g_instance.attr.attr_storage.cstore_buffers (1024 Mbytes) or shared memory (1894 Mbytes) is larger.
=========================================
Successfully started.
[omm@enmoedu ~]$ 

• 登录opengauss 3.0.0 数据库

[omm@enmoedu ~]$ gsql -d postgres -p 15400 -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:34 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

openGauss=# 

--进入数据库omm，创建表空间、创建数据库
drop DATABASE  IF EXISTS  musicdb;
drop DATABASE  IF EXISTS  musicdb1;
drop DATABASE  IF EXISTS  musicdb2;
drop DATABASE  IF EXISTS  musicdb3;
drop tablespace IF EXISTS music_tbs;

CREATE TABLESPACE music_tbs RELATIVE LOCATION 'tablespace/test_ts1';
CREATE DATABASE musicdb1  WITH TABLESPACE = music_tbs;
CREATE DATABASE musicdb2  WITH TABLESPACE = music_tbs;
CREATE DATABASE musicdb3  WITH TABLESPACE = music_tbs;

--执行下面的SQL语句，创建用户user1：
CREATE USER user1 IDENTIFIED BY 'enmoedu@1234';

5 给予新建的数据库权限

--授予user1数据库系统的SYSADMIN权限：
ALTER USER user1 SYSADMIN;

6 使用数据库用户user1登录到数据库musicdb1，创建一个表t11，并插入一条数