这篇文章主要介绍CDB和PDB的基本管理,资料来源oracle官方。

基本概念:

Multitenant Environment:多租户环境

CDB(Container Database):数据库容器

PD(Pluggable Database):可插拔数据库

CDB与PDB关系图

COMMON USERS(普通用户):经常建立在CDB层,用户名以C##或c##开头;

LOCAL USERS(本地用户):仅建立在PDB层,建立的时候得指定CONTAINER。

在oracle 12c中,使用了一个container(容器)的概念,让我们先看看官方的对它的介绍,为了保留最原始的意思,这里引用英文而不翻译了。

The data dictionary in each container in a CDB is separate, and the current container is the container whose data dictionary is used for name resolution and for privilege authorization. The current container can be the root or a PDB. Each session has exactly one current container at any point in time, but it is possible for a session to switch from one container to another.

Each container has a unique ID and name in a CDB. You can use the CON_ID and CON_NAME parameters in the USERENV namespace to determine the current container ID and name with the SYS_CONTEXT function.

1、查看Oracle 12c的版本


SQL> select * from v$version;

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SQL>select sys_context (\'USERENV\', \'CON_NAME\') from dual; 
SYS_CONTEXT(\'USERENV\',\'CON_NAME\') 
----------------------------------------------------------------------------------------------------
 CDB$ROOT

2、我们可以通过ALTER SESSION SET CONTAINER 指定其他容器

SQL>select con_id,dbid,NAME,OPEN_MODE from v$pdbs;

3、将Pdb open:

SQL> alter pluggable database pdborcl open;

4、查看容器

SQL>select con_id,dbid,NAME,OPEN_MODE from v$pdbs;

5、切换容器到pdb

SQL> alter session set container=PDBORCL;

6、查看当前使用容器

SQL>select sys_context (\'USERENV\', \'CON_NAME\') from dual;

7、创建用户

SQL>create user informix identified by gmgl;

SQL>grant dba to informix;