1.前言
CDB与PDB是Oracle 12C引入的新特性，在ORACLE 12C数据库引入的多租用户环境（Multitenant Environment）中，允许一个数据库容器（CDB）承载多个可插拔数据库（PDB）。CDB全称为ContainerDatabase，中文翻译为数据库容器，PDB全称为Pluggable Database，即可插拔数据库。在ORACLE 12C之前，实例与数据库是一对一或多对一关系（RAC）：即一个实例只能与一个数据库相关联，数据库可以被多个实例所加载。而实例与数据库不可能是一对多的关系。当进入ORACLE 12C后，实例与数据库可以是一对多的关系。
关于CDB与PDB的关系图
12c中 oracle引入了容器数据库 CDB（container database），和可插拔数据库 PDB（pluggable database）。oracle 将CDB看成一个容器，用来存放数据库。
在CDB中可以有多个PDB，其中存在一个root根容器（PDB$ROOT）、一个种子容器（PDB$SEED）和多个PDBS。所有的PDB共用一个硬件系统资源、sga和pga、redo、临时段、控制文件、参数文件、还原段（还可对每个PDB单独指定）。
PDB$ROOT：根容器用来做所有容器的跟，用来对每个PDB进行统一管理，sqlplus / as sysdba连接进来默认是连接的根容器，需要切换到其他的PDB容器才可以对单独的PDB操作。其中有 system数据文件、sysaux数据文件、（undo数据文件、temp数据文件、redo、控制文件）。一般不存放生产数据文件
PDB$SEED：种子容器作为插入PDB的模板而存在，每个CDB都有一个种子容器，且不可对其中对象进行修改。其中有 system数据文件、sysaux数据文件、其他数据文件。
PDB：新插入容器，该容器用来存放数据库。其中有 system数据文件、sysaux数据文件、其他数据文件。12c中可以插入多个容器进行统一管理，来减少BDA的工作量。其中的数据库可以插入或拔出。
用户：12c中PDB$ROOT中的普通目录可以通过权限分配来访问一个或多个指定的PDB容器，最大权限用户是sysdba。其中PDB也可单独创建普通用户来管理该容器的数据库。
PDB资源管理：12c中将多个数据库运行在一个硬件资源上，CDB性能上得到优化。在CDB中为每个PDB确定使用CPU最低份额，CDB会按照一个PDB份额/分配的总份额数*100%，来保证PDB最低份额数。
容器管理
连接数据库
[oracle@master ~]$ sqlplus / as sysdba
查询该容器是CDB 还是非CDB
SQL> select name,cdb,open_mode,con_id from v$database; NAME CDB OPEN_MODE CON_ID --------- --- -------------------- ---------- ORCL YES READ WRITE 0
查看当前容器
SQL> show con_name; CON_NAME ------------------------------ CDB$ROOT
查看所创建的PDB
SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 3 PDBORCL MOUNTED
创建一个新PDB
SQL> create pluggable database pdb1 admin user pdb1 identified by pdb1 file_name_convert=('/u01/app/oracle/oradata/orcl/pdbseed/','/u01/app/oracle/oradata/orcl/pdb1/'); Pluggable database created. SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 3 PDBORCL MOUNTED 4 PDB1 MOUNTED
启动一个创建好的PDB
SQL> alter pluggable database pdb1 open; Warning: PDB altered with errors. SQL> select message,time from pdb_plug_in_violations; MESSAGE -------------------------------------------------------------------------------- TIME --------------------------------------------------------------------------- Sync PDB failed with ORA-959 during 'CREATE USER c##dm_ca IDENTIFIED BY * PROFIL E DEFAULT DEFAULT TABLESPACE casdb ACCOUNT UNLOCK container = all' 26-DEC-18 11.26.27.070262 AM SQL> alter session set container=pdb1; Session altered. SQL> create tablespace users datafile '/u01/app/oracle/oradata/orcl/pdb1/users01.dbf' size 800M; Tablespace created. SQL> alter pluggable database pdb1 close; Pluggable database altered. SQL> alter pluggable database pdb1 open; Warning: PDB altered with errors. #还是会报错，不知是何原因了，查看没有报错信息 SQL> select message,time from pdb_plug_in_violations; no rows selected SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 4 PDB1 READ WRITE YES
也可以通过sqlplus使用传统的startup和shutdown命令来启动和关闭PDB
SQL> alter session set container=pdb1; Session altered. SQL> SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 4 PDB1 MOUNTED SQL> startup Warning: PDB altered with errors. Pluggable Database opened. SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 4 PDB1 READ WRITE YES SQL> shutdown immediate; Pluggable Database closed. SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 4 PDB1 MOUNTED SQL> alter session set container=CDB$ROOT; Session altered.
配置监听文件
监听文件目录在$ORACLE_HOME/network/admin
[oracle@master admin]$ cat tnsnames.ora # tnsnames.ora Network Configuration File: /u01/app/oracle/product/12.1.0/db_1/network/admin/tnsnames.ora # Generated by Oracle configuration tools. ORCL = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = master)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = orcl) ) ) PDBORCL = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = master)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = PDBORCL) ) ) PDB1 = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.200)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = PDB1) ) )
listener.ora 文件内容
[oracle@master admin]$ cat listener.ora # listener.ora Network Configuration File: /u01/app/oracle/product/12.1.0/db_1/network/admin/listener.ora # Generated by Oracle configuration tools. SID_LIST_LISTENER = (SID_LIST = (SID_DESC = (GLOBAL_DBNAME = orcl) (ORACLE_HOME = /u01/app/oracle/product/12.1.0/db_1) (SID_NAME = ORCL) )
(SID_DESC=
(GLOBAL_DBNAME = PDB1)
(SID_NAME = PDB1)
) ) LISTENER = (DESCRIPTION_LIST = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = master)(PORT = 1521)) ) (DESCRIPTION = (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521)) ) ) ADR_BASE_LISTENER = /u01/app/oracle
测试一下
[oracle@master admin]$ tnsping pdb1 TNS Ping Utility for Linux: Version 12.1.0.2.0 - Production on 26-DEC-2018 11:55:36 Copyright (c) 1997, 2014, Oracle. All rights reserved. Used parameter files: /u01/app/oracle/product/12.1.0/db_1/network/admin/sqlnet.ora Used TNSNAMES adapter to resolve the alias Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.200)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = PDB1))) OK (0 msec)
连接pdb1
方法一：
[oracle@master admin]$ sqlplus sys/admin@pdb1 as sysdba SQL*Plus: Release 12.1.0.2.0 Production on Wed Dec 26 14:23:22 2018 Copyright (c) 1982, 2014, Oracle. All rights reserved. Connected to: Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options SQL> startup Warning: PDB altered with errors. Pluggable Database opened. SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 4 PDB1 READ WRITE YES SQL>
方法二：
[oracle@master ~]$ sqlplus pdb1/pdb1@pdb1
SQL*Plus: Release 12.1.0.2.0 Production on Wed Dec 26 15:27:35 2018
Copyright (c) 1982, 2014, Oracle. All rights reserved.
Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
SQL>
oracle12C中在启动数据库的时候，PDB并不会随着CDB而启动。不过我们可以通过创建一个触发器让PDB能够随CDB启动。如下：
SQL> alter session set container=CDB$ROOT; Session altered. SQL> SHOW CON_NAME CON_NAME ------------------------------ CDB$ROOT SQL> CREATE OR REPLACE TRIGGER open_pdbs AFTER STARTUP ON DATABASE BEGIN EXECUTE IMMEDIATE 'ALTER PLUGGABLE DATABASE ALL OPEN'; END open_pdbs; / Trigger created.
重新启动数据库：
[oracle@master ~]$ sqlplus / as sysdba SQL*Plus: Release 12.1.0.2.0 Production on Wed Dec 26 14:32:11 2018 Copyright (c) 1982, 2014, Oracle. All rights reserved. Connected to: Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 3 PDBORCL READ WRITE NO 4 PDB1 READ WRITE YES
确实已经随着数据库启动，pdb1也启动起来。
但是，RESTRICTED 为YES
我重新创建一个pdb2
SQL> show con_name; CON_NAME ------------------------------ CDB$ROOT SQL> create pluggable database pdb2 admin user pdb2 identified by pdb2 file_name_convert=('/u01/app/oracle/oradata/orcl/pdbseed/','/u01/app/oracle/oradata/orcl/pdb2/'); Pluggable database created. SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 3 PDBORCL READ WRITE NO 4 PDB1 READ WRITE YES 5 PDB2 MOUNTED SQL> alter pluggable database pdb2 open; Pluggable database altered. SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 3 PDBORCL READ WRITE NO 4 PDB1 READ WRITE YES 5 PDB2 READ WRITE NO
pdb2完全正确。
pdb1解决如下：
SQL> select message from pdb_plug_in_violations where name='PDB1'; MESSAGE -------------------------------------------------------------------------------- Sync PDB failed with ORA-959 during 'CREATE USER c##dm_ca IDENTIFIED BY * PROFIL E DEFAULT DEFAULT TABLESPACE casdb ACCOUNT UNLOCK container = all' Sync PDB failed with ORA-1918 during 'drop user c##dm_ca cascade' SQL> alter session set container=PDB1; Session altered. SQL> select name from v$tablespace; NAME ------------------------------ UNDOTBS1 SYSTEM SYSAUX TEMP USERS SQL> create tablespace casdb datafile '/u01/app/oracle/oradata/orcl/pdb1/casdb01.dbf' size 800M; Tablespace created. SQL> conn / as sysdba Connected. SQL> alter pluggable database pdb1 close; Pluggable database altered. SQL> alter pluggable database pdb1 open; Pluggable database altered. SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 3 PDBORCL READ WRITE NO 4 PDB1 READ WRITE NO 5 PDB2 READ WRITE NO SQL>