番外：如何克隆可刷新的PDB（Refreshable PDB）

基於版本：19c （12.2.0.3） AskScuti

建立方法：克隆建立

對應路徑：屬於克隆。PDB類型爲：Refreshable

相關係列請參考《Oracle建立PDB列表文章》

注意：建立可刷新的PDB，源庫必須處於歸檔模式和本地UNDO模式

 

內容總覽 

1. 環境概述

2. 檢查源庫環境

3. 源庫建立用戶並受權

4. 目標庫編輯TNS

5. 目標庫建立DBLink

6. 目標庫建立可刷新PDB

7. 目標庫打開可刷新PDB

8. 可刷新PDB測試

 

1. 環境概述

爲了概念理解統一，提早約定下：

遠程CDB2中有個ERP1，咱們稱遠程CDB2爲「源CDB」，IP：192.168.1.14

本地CDB1中有個PDB1，咱們稱本地CDB1爲「目標CDB」，IP：192.168.1.12

注意：源CDB和目標CDB是相對而言。就是被克隆的對象叫「源」，準備克隆出來的對象叫「目標」。所以，下面就是要經過源CDB2中的ERP1，遠程克隆出來一個可刷新的PDB，放在目標CDB1中，名稱爲PDB_REF。

 

2. 檢查源庫環境

檢查是否爲歸檔模式

[oracle@henry ~]$ rlwrap sqlplus / as sysdba SQL*Plus: Release 19.0.0.0.0 - Production on Sat Aug 31 07:27:48 2019 Version 19.3.0.0.0 Copyright (c) 1982, 2019, Oracle.  All rights reserved. Connected to: Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production Version 19.3.0.0.0 SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- --------- ---------- ----------
     2 PDB$SEED      READ ONLY NO 3 ERP1 READ WRITE NO SQL> archive log list; Database log mode 　 Archive Mode Automatic archival Enabled Archive destination /u01/app/oracle/arch1 Oldest online log sequence     5
Next log sequence to archive   7
Current log sequence           7

 

檢查是否爲本地UNDO

SQL> select property_name,property_value from database_properties where property_name='LOCAL_UNDO_ENABLED'; PROPERTY_NAME PROPERTY_VALUE -------------------- --------------------
LOCAL_UNDO_ENABLED   TRUE

 

3. 源庫建立用戶並受權

SQL> create user c##u1 identified by oracle; User created. SQL> grant create session,create pluggable database,sysoper to c##u1 container=all; Grant succeeded.

 

4. 目標庫編輯TNS

CDB2 = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.14)(PORT = 1521)) ) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = CDB2) ) )

目標庫編輯tnsnames別名，指向源庫。

 

5. 目標庫建立DBLink

SQL> create database link cdb2_dblink connect to c##u1 identified by oracle using 'CDB2'; Database link created. #測試DBLINK SQL> select * from tab@cdb2_dblink; no rows selected

 

6. 目標庫建立可刷新PDB

注意：刷新模式子句只支持 CREATE PLUGGABLE DATABASE ... FROM 語句。

6.0 基於默認 REFRESH MODE NONE

默認缺省狀況下，建立普通PDB（非刷新PDB）

 

6.1 基於手工刷新 REFRESH MODE MANUAL

SQL> !mkdir /u01/app/oracle/oradata/CDB1/pdbref SQL> create pluggable database pdb_ref from erp1@cdb2_dblink create_file_dest='/u01/app/oracle/oradata/CDB1/pdbref' refresh mode manual;

 

6.2 基於自動刷新 REFRESH MODE EVERY number_of_minutes MINUTES

SQL> !mkdir /u01/app/oracle/oradata/CDB1/pdbrefauto SQL> create pluggable database pdb_refauto from erp1@cdb2_dblink create_file_dest='/u01/app/oracle/oradata/CDB1/pdbrefauto' refresh mode every 60 minutes;

 

查看

SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- --------- ---------- ----------
     2 PDB$SEED      READ ONLY NO 3 PDB1 MOUNTED 4 PDB_REF MOUNTED 5 PDB_REFAUTO MOUNTED

 

7. 目標庫打開可刷新PDB

可刷新PDB爲了保證和源庫一致，必須只能以 READ ONLY 只讀模式打開。

SQL> alter pluggable database pdb_ref open read only; Pluggable database altered. SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- --------- ---------- ----------
     2 PDB$SEED      READ ONLY NO 3 PDB1 MOUNTED 4 PDB_REF       READ ONLY NO 5 PDB_REFAUTO   MOUNTED

沒法以讀寫模式打開

SQL> alter pluggable database pdb_ref open; alter pluggable database pdb_ref open
* ERROR at line 1: ORA-65341: cannot open pluggable database in read/write mode

 

8. 可刷新PDB測試

8.1 源庫建立測試數據

SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- --------- ---------- ----------
     2 PDB$SEED      READ ONLY NO 3 ERP1          READ WRITE NO SQL> alter session set container=erp1; Session altered. SQL> create table test_ref(id number); Table created. SQL> insert into test_ref select object_id from dba_objects where rownum<501; 500 rows created. SQL> commit; Commit complete. SQL> select count(*) from test_ref; COUNT(*) ----------
       500

 

8.2 目標庫刷新

刷新前查看

SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- --------- ---------- ----------
     2 PDB$SEED      READ ONLY NO 3 PDB1 MOUNTED 4 PDB_REF       READ ONLY NO 5 PDB_REFAUTO MOUNTED SQL> alter session set container=pdb_ref; Session altered. SQL> select count(*) from test_ref; select count(*) from test_ref * ERROR at line 1: ORA-00942: table or view does not exist

 

目標庫關閉PDB_REF進行手工刷新

注意：執行刷新時，必須關閉可刷新的PDB。若是嘗試自動刷新時未關閉可刷新的PDB，則將刷新延遲到下一次計劃。若是執行手動刷新時未關閉可刷新的PDB，則會報告錯誤。自動刷新模式的PDB也能夠執行手工刷新。

SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- --------- ---------- ----------
     4 PDB_REF       READ ONLY NO 
SQL> alter pluggable database pdb_ref close immediate; Pluggable database altered. SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- --------- ---------- ----------
     4 PDB_REF MOUNTED 
SQL> alter pluggable database pdb_ref refresh; Pluggable database altered.

 

8.3 目標庫刷新後查看

SQL> alter pluggable database pdb_ref open read only; Pluggable database altered. SQL> show pdbs CON_ID CON_NAME OPEN MODE RESTRICTED ---------- --------- ---------- ----------
     4 PDB_REF       READ ONLY NO SQL> select count(*) from test_ref; COUNT(*) ----------
       500