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Oracle 12.2 新特性:在线PDB数据库克隆(Pluggable Hot Clone)
modb.pro

在Oracle 12c的多租户(Multitenant)特性中,可以通过灵活的克隆复制来创建PDB(Pluggable Database),使得运维的工作大大简化。但是在12.1中,进行数据库Clone时,源数据库需要置于Read Only模式,即影响源数据库的使用,又会带来时间窗口的不便。

在12.2中,Oracle引入了 Hot Clone 技术,可以通过在线的方式,对源库进行复制。大大简化的运维的复杂性。

PDBHotClone.jpg

以下测试向大家展示了这一新特性的用法和功能。首先在PDB1执行一个数据表的连续插入动作,维持活动事务(注意:最后中断是因为克隆已经完成了):

SQL> connect eygle/eygle@pdb1
Connected.
SQL> create table enmotech ( id number, dt timestamp );

Table created.

Elapsed: 00:00:01.17
SQL> begin
  2   for i in 1 .. 600 loop
  3  	insert into enmotech values (i, systimestamp );
  4  	commit;
  5  	dbms_lock.sleep(2);
  6   end loop;
  7  end;
  8  /
^Cbegin
*
ERROR at line 1:
ORA-01013: user requested cancel of current operation
ORA-06512: at "SYS.DBMS_LOCK", line 205
ORA-06512: at line 5


Elapsed: 00:04:20.96

选择PDB1作为克隆复制的源数据库,在源数据库保持活动的状态下,进行Clone复制:

[oracle@pg1-enmotech-com ~]$ sqlplus / as sysdba

SQL*Plus: Release 12.2.0.1.0 Production on Thu Dec 1 03:22:50 2016

Copyright (c) 1982, 2016, Oracle.  All rights reserved.


Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

SQL> select con_id,name from v$datafile where con_id=3;

    CON_ID
----------
NAME
--------------------------------------------------------------------------------
	 3
/u01/app/oracle/oradata/ORCL/3F605C8D8A4206B6E0536838A8C04ACF/datafile/o1_mf_system_d0n37tyk_.dbf

	 3
/u01/app/oracle/oradata/ORCL/3F605C8D8A4206B6E0536838A8C04ACF/datafile/o1_mf_sysaux_d0n37tyx_.dbf

	 3

    CON_ID
----------
NAME
--------------------------------------------------------------------------------
/u01/app/oracle/oradata/ORCL/3F605C8D8A4206B6E0536838A8C04ACF/datafile/o1_mf_undotbs1_d0n37tyy_.dbf

	 3
/u01/app/oracle/oradata/ORCL/3F605C8D8A4206B6E0536838A8C04ACF/datafile/o1_mf_users_d0n38fdr_.dbf

接下来执行数据库克隆的操作,无需对源库执行任何操作:

SQL> ! mkdir /u01/app/oracle/oradata/ORCL/enmotech

SQL> alter system set db_create_file_dest='/u01/app/oracle/oradata/ORCL/enmotech';

System altered.

SQL> create pluggable database yhem from pdb1 ;

Pluggable database created.

克隆复制完成之后,可以打开数据库,查看数据,之前的事务数据已经被部分的复制过来:

SQL> alter pluggable database yhem open;

Pluggable database altered.

SQL> alter session set container=YHEM;

Session altered.

SQL> alter session set current_schema=EYGLE;

Session altered.

SQL> select count(*) from enmotech;

  COUNT(*)
----------
	10

SQL> select * from enmotech; 

	ID DT
---------- ------------------------------------------------------
	 1 01-DEC-16 03.37.06.539694 AM
	 2 01-DEC-16 03.37.08.556754 AM
	 3 01-DEC-16 03.37.10.558066 AM
	 4 01-DEC-16 03.37.12.563268 AM
	 5 01-DEC-16 03.37.14.564449 AM
	 6 01-DEC-16 03.37.16.570639 AM
	 7 01-DEC-16 03.37.18.571286 AM
	 8 01-DEC-16 03.37.20.571668 AM
	 9 01-DEC-16 03.37.22.903123 AM
	10 01-DEC-16 03.37.24.902948 AM

10 rows selected.

通过告警日志记录的信息,可以看到整个动作的核心步骤,实际上Oracle做了不完全恢复,最后在指定的SCN打开了数据库:

2016-12-01T03:35:43.207319+08:00
ALTER SYSTEM SET db_create_file_dest='/u01/app/oracle/oradata/ORCL/enmotech' SCOPE=BOTH;
2016-12-01T03:37:08.934023+08:00
create pluggable database yhem from pdb1 
2016-12-01T03:37:08.989913+08:00
PDB1(3): AUDSYS.AUD$UNIFIED (SQL_TEXT) - CLOB populated
2016-12-01T03:37:29.640510+08:00
YHEM(5):Endian type of dictionary set to little
****************************************************************
Pluggable Database YHEM with pdb id - 5 is created as UNUSABLE.
If any errors are encountered before the pdb is marked as NEW,
then the pdb must be dropped
local undo-1, localundoscn-0x00000000000000e0
****************************************************************
YHEM(5):Media Recovery Start
2016-12-01T03:37:30.026018+08:00
YHEM(5):Serial Media Recovery started
2016-12-01T03:37:30.154319+08:00
YHEM(5):Recovery of Online Redo Log: Thread 1 Group 2 Seq 68 Reading mem 0
YHEM(5):  Mem# 0: /u01/app/oracle/oradata/ORCL/onlinelog/o1_mf_2_d0n2yzro_.log
YHEM(5):  Mem# 1: /u01/app/oracle/fast_recovery_area/orcl/ORCL/onlinelog/o1_mf_2_d0n2z0vm_.log
2016-12-01T03:37:30.346568+08:00
YHEM(5):Incomplete Recovery applied until change 2198639 time 12/01/2016 03:37:26
2016-12-01T03:37:30.353390+08:00
YHEM(5):Media Recovery Complete (orcl)
YHEM(5):Autotune of undo retention is turned on. 
2016-12-01T03:37:36.701219+08:00
YHEM(5):[15846] Successfully onlined Undo Tablespace 2.
YHEM(5):Undo initialization finished serial:0 start:139692076 end:139692182 diff:106 ms (0.1 seconds)
YHEM(5):Database Characterset for YHEM is AL32UTF8
YHEM(5):JIT: pid 15846 requesting stop
Completed: create pluggable database yhem from pdb1 
2016-12-01T03:38:32.727311+08:00
alter pluggable database yhem open
YHEM(5):Autotune of undo retention is turned on. 
2016-12-01T03:38:32.850162+08:00
YHEM(5):Endian type of dictionary set to little
YHEM(5):[15846] Successfully onlined Undo Tablespace 2.
YHEM(5):Undo initialization finished serial:0 start:139748579 end:139748829 diff:250 ms (0.2 seconds)
YHEM(5):Deleting old file#9 from file$ 
YHEM(5):Deleting old file#10 from file$ 
YHEM(5):Deleting old file#11 from file$ 
YHEM(5):Deleting old file#12 from file$ 
YHEM(5):Deleting old file#13 from file$ 
YHEM(5):Adding new file#18 to file$(old file#9) 
YHEM(5):Adding new file#19 to file$(old file#10) 
YHEM(5):Adding new file#20 to file$(old file#11) 
YHEM(5):Adding new file#21 to file$(old file#12) 
YHEM(5):Successfully created internal service yhem at open
****************************************************************
Post plug operations are now complete.
Pluggable database YHEM with pdb id - 5 is now marked as NEW.
****************************************************************
YHEM(5):Database Characterset for YHEM is AL32UTF8
2016-12-01T03:38:33.998091+08:00
YHEM(5):Opatch validation is skipped for PDB YHEM (con_id=0)
2016-12-01T03:39:01.596335+08:00
YHEM(5):Opening pdb with no Resource Manager plan active
2016-12-01T03:39:12.433441+08:00
Pluggable database YHEM opened read write
Completed: alter pluggable database yhem open
2016-12-01T03:46:45.511090+08:00
Starting control autobackup

Control autobackup written to DISK device

handle '/u01/app/oracle/fast_recovery_area/orcl/PG1/autobackup/2016_12_01/o1_mf_s_929418405_d3yc55s5_.bkp'


这就是Oracle 12.2的重要增强之一,关于PDB的持续改进。


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By eygle on 2016-12-08 18:43 | Comments (0) | Oracle12c/11g | 3222 |


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