1.前言
CDB與PDB是Oracle 12C引入的新特性，在ORACLE 12C數據庫引入的多租用戶環境（Multitenant Environment）中，允許一個數據庫容器（CDB）承載多個可插拔數據庫（PDB）。CDB全稱為ContainerDatabase，中文翻譯為數據庫容器，PDB全稱為Pluggable Database，即可插拔數據庫。在ORACLE 12C之前，實例與數據庫是一對一或多對一關系（RAC）：即一個實例只能與一個數據庫相關聯，數據庫可以被多個實例所加載。而實例與數據庫不可能是一對多的關系。當進入ORACLE 12C后，實例與數據庫可以是一對多的關系。
關於CDB與PDB的關系圖
12c中 oracle引入了容器數據庫 CDB（container database），和可插拔數據庫 PDB（pluggable database）。oracle 將CDB看成一個容器，用來存放數據庫。
在CDB中可以有多個PDB，其中存在一個root根容器（PDB$ROOT）、一個種子容器（PDB$SEED）和多個PDBS。所有的PDB共用一個硬件系統資源、sga和pga、redo、臨時段、控制文件、參數文件、還原段（還可對每個PDB單獨指定）。
PDB$ROOT：根容器用來做所有容器的跟，用來對每個PDB進行統一管理，sqlplus / as sysdba連接進來默認是連接的根容器，需要切換到其他的PDB容器才可以對單獨的PDB操作。其中有 system數據文件、sysaux數據文件、（undo數據文件、temp數據文件、redo、控制文件）。一般不存放生產數據文件
PDB$SEED：種子容器作為插入PDB的模板而存在，每個CDB都有一個種子容器，且不可對其中對象進行修改。其中有 system數據文件、sysaux數據文件、其他數據文件。
PDB：新插入容器，該容器用來存放數據庫。其中有 system數據文件、sysaux數據文件、其他數據文件。12c中可以插入多個容器進行統一管理，來減少BDA的工作量。其中的數據庫可以插入或拔出。
用戶：12c中PDB$ROOT中的普通目錄可以通過權限分配來訪問一個或多個指定的PDB容器，最大權限用戶是sysdba。其中PDB也可單獨創建普通用戶來管理該容器的數據庫。
PDB資源管理：12c中將多個數據庫運行在一個硬件資源上，CDB性能上得到優化。在CDB中為每個PDB確定使用CPU最低份額，CDB會按照一個PDB份額/分配的總份額數*100%，來保證PDB最低份額數。
容器管理
連接數據庫
[oracle@master ~]$ sqlplus / as sysdba
查詢該容器是CDB 還是非CDB
SQL> select name,cdb,open_mode,con_id from v$database; NAME CDB OPEN_MODE CON_ID --------- --- -------------------- ---------- ORCL YES READ WRITE 0
查看當前容器
SQL> show con_name; CON_NAME ------------------------------ CDB$ROOT
查看所創建的PDB
SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 3 PDBORCL MOUNTED
創建一個新PDB
SQL> create pluggable database pdb1 admin user pdb1 identified by pdb1 file_name_convert=('/u01/app/oracle/oradata/orcl/pdbseed/','/u01/app/oracle/oradata/orcl/pdb1/'); Pluggable database created. SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 2 PDB$SEED READ ONLY NO 3 PDBORCL MOUNTED 4 PDB1 MOUNTED
啟動一個創建好的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. #還是會報錯，不知是何原因了，查看沒有報錯信息 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
也可以通過sqlplus使用傳統的startup和shutdown命令來啟動和關閉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$ROOT; Session altered.
配置監聽文件
監聽文件目錄在$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 文件內容
[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
測試一下
[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)
連接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中在啟動數據庫的時候，PDB並不會隨着CDB而啟動。不過我們可以通過創建一個觸發器讓PDB能夠隨CDB啟動。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.
重新啟動數據庫：
[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$SEED READ ONLY NO 3 PDBORCL READ WRITE NO 4 PDB1 READ WRITE YES
確實已經隨着數據庫啟動，pdb1也啟動起來。
但是，RESTRICTED 為YES
我重新創建一個pdb2
SQL> show con_name; CON_NAME ------------------------------ CDB$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完全正確。
pdb1解決如下：
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>